Irritable Bowel Syndrome (IBS)

Irritable Bowel Syndrome (IBS)

Contributor(s): Dr. Maureen Williams, ND; Debra Gordon, MS; Dr. Shayna Sandhaus, PhD

1 Overview

Summary and Quick Facts

  • Irritable bowel syndrome (IBS) is characterized by chronic abdominal pain, bloating and varying bouts of diarrhea and constipation. The causes are not always clear, but many factors may contribute to IBS. IBS should not be confused with inflammatory bowel disease.
  • This protocol will review several potential causes of IBS and how it is diagnosed. A comprehensive approach to IBS management that combines conventional treatments with dietary, lifestyle and natural interventions will be presented, as well.
  • Following a recommended diet, managing stress and combining conventional medications with natural compounds may help alleviate symptoms of IBS and improve one’s overall quality of life.
  • Peppermint oil, alone or in combination with caraway oil, has been shown to significantly improve symptoms of IBS.

What is Irritable Bowel Syndrome?

Irritable bowel syndrome (IBS) is a functional (ie, not linked to tissue damage or other biological markers) gastrointestinal disorder characterized by chronic abdominal pain, bloating, and varying bouts of diarrhea and constipation. Importantly, IBS should not be confused with inflammatory bowel disease, a broad term describing conditions characterized by chronic inflammation of the gastrointestinal tract.

IBS symptoms may be improved with dietary and lifestyle changes; however, more serious cases could require pharmacologic interventions. Associated psychological conditions like depression must be treated as well, or common drug therapies may not be effective. IBS is very common and generally associated with reduced quality of life.

Natural interventions such as probiotics and artichoke may help alleviate IBS symptoms and improve gut health.

What are Risk Factors for Irritable Bowel Syndrome?

  • Genetic predisposition
  • Stress, anxiety, and/or depression
  • Food sensitivities
  • Overgrowth of small intestinal bacteria
  • Hormonal fluctuations
  • Certain medications, including proton pump inhibitors and broad-spectrum antibiotics
  • Gastrointestinal infections

What are the Signs and Symptoms of Irritable Bowel Syndrome?

  • Abdominal pain that is relieved with defecation and associated with change in stool frequency or appearance
    • Changes in stool could include constipation (IBS-C) or diarrhea (IBS-D)
  • Other symptoms not directly associated with the gastrointestinal tract may include headaches, backaches, and lethargy

What are Conventional Medical Treatments for Irritable Bowel Syndrome?

  • Bulking agents like dietary fiber
  • Laxatives and stool softeners (eg, lubiprostone [Amitiza] and polyethylene glycol [MiraLAX])
  • Antispasmodic medications (eg, propantheline [Probanthine])
  • Serotonergic antidepressants, either centrally acting (eg, duloxetine [Cymbalta]) or locally acting (eg, alosetron [Lotronex])
  • Antibiotics to treat small intestinal bacterial overgrowth; however, probiotics may become a more popular option

What are Emerging Therapies for Irritable Bowel Syndrome?

  • Hormone restoration therapy
  • Linaclotide (Linzess), a stool softener that can also relieve abdominal pain
  • Mesalazine, a drug used to treat inflammatory bowel disease, may also benefit patients with irritable bowel syndrome.

What Dietary and Lifestyle Changes Can Be Beneficial for Irritable Bowel Syndrome?

  • Consider certain elimination diets (ie, low FODMAP or gluten-free diet); foods to avoid may include legumes, wheat, barley, rye, milk, certain fruits, and others.
  • Get tested for and avoid foods that trigger IgG (ie, foods that cause sensitivities)
  • Stress reduction techniques (eg, meditation, cognitive therapy, etc.)
  • Engage in a regular form of exercise
  • Consider acupuncture

What Natural Interventions May Be Beneficial for Irritable Bowel Syndrome?

  • Buffered vitamin C powder. Powders containing vitamin C (ascorbic acid) and minerals like potassium and magnesium, when taken on an empty stomach, can induce colon peristalsis to support complete bowel evacuation.
  • Peppermint oil/caraway oil. Peppermint oil, alone or in combination with caraway oil, can significantly improve IBS symptoms.
  • Probiotics. As alterations in the gut microbiome can cause or exacerbate IBS symptoms, supplementation with probiotic bacteria or yeast may help rebalance it. Many patients taking probiotics experience improvements in their symptoms.
  • Artichoke. Artichoke supports healthy digestive function by promoting bile production. In one study, artichoke leaf extract almost eliminated abdominal pain, cramps, bloating, flatulence, and constipation in patients with IBS.
  • Melatonin. Melatonin, a multifunctional hormone, can be useful for more than just improving sleep. IBS patients taking melatonin had reduced abdominal pain and bloating.
  • Perilla leaf extract. Perilla leaf extract, a plant from the mint family, is rich in polyphenols and has been demonstrated benefits for digestive ailments. Studies indicate it can offer relief for abdominal discomfort and may help reduce stress.
  • Other natural interventions that may provide benefits for people with IBS include curcumin and adaptogenic herbs such as Rhodiola rosea and bacopa.

2 Introduction

Irritable bowel syndrome (IBS) is a very common gastrointestinal disorder, estimated to be present in about 11-15% of the global population (Lovell 2012; Mearin 2012; Mayer 2008; NDDIC 2012; Mayo Clinic 2011). Typical IBS symptoms include chronic abdominal pain, bloating, and varying bouts of diarrhea and constipation. The condition is generally associated with a reduced quality of life (Mayer 2008). IBS is a functional disorder, and as such has not been consistently linked to tissue damage or other biological markers that can be tested clinically (Mayer 2008; Torpy 2011). It is thought to be largely underdiagnosed (Trinkley 2011; Mearin 2012; Lee 2012; Mayer 2008).

IBS should not be confused with inflammatory bowel disease (IBD). IBD includes Crohn’s disease and ulcerative colitis, which are characterized by inflammatory lesions in the intestines (Duigenan 2012).

Many are unaware that multiple factors may cause or exacerbate IBS symptoms. For example, stress, anxiety, depression, food sensitivities, small intestinal bacterial overgrowth, and hormonal fluctuations are all associated with IBS (Greenwood-Van Meerveld 2001; Reddymasu 2010; Yakoob 2011; Sachdeva 2011; Atkinson 2004).

Treatment of psychological conditions in IBS patients is especially important because irritable bowel symptoms often persist despite drug therapy if these issues are not addressed (Lydiard 1999, 2001; Asahina 2006; Chang 2011; Mayer 2001; Ford 2009; Zijdenbos 2009; Hayee 2007).

This protocol will discuss the causes of and risk factors for IBS along with its diagnosis and conventional treatment; emerging drug strategies will be examined as well. The important role of dietary and lifestyle modification will be reviewed, and data on scientifically studied natural compounds that may alleviate IBS symptoms will also be presented.

3 Causes and Risk Factors

The cause(s) of IBS are not clear (Torpy 2011). Stress, altered gut bacteria, genetics, and food sensitivities may all be involved (Spiller 2012). One theory proposes that altered serotonin metabolism within the gastrointestinal (GI) tract and/or abnormalities in pain perception pathways causes hypersensitivity to abdominal pain (Kanazawa 2011; Spiller 2007; Mayer 2008), while other hypotheses have pointed to stress-induced inflammation, gastroenteritis, and a history of traumatic events as factors that contribute to the development of IBS (Spiller 2012; Lee 2012).

Disrupted brain-gut communication

Some evidence suggests that altered communication between the brain and gut may contribute to pain hypersensitivity and/or motility disturbances in IBS (Fichna 2012; Stasi 2012; Mach 2004; Orr 1997). The mechanisms behind these phenomena are unclear, but some studies have identified altered autonomic and central nervous function in individuals with IBS (Orr 1997; Azpiroz 2002; Jarrett 2003). Another study employed magnetic resonance imaging to examine the brains of people with IBS and identified some structural changes that may contribute to enteric hypersensitivity (Davis 2008). Stress and anxiety appear to contribute, at least in part, to gut hypersensitivity via modulation of neural pain-processing pathways by glucocorticoid hormones, which are also called “stress hormones” (Greenwood-Van Meerveld 2001). Another aspect of this impaired brain-gut communication may stem from altered levels of chemical messengers called neurotransmitters. Levels and activity of the neurotransmitter serotonin in particular appear to be somewhat abnormal in people with IBS (Dunlop 2005; Atkinson 2006).

Small intestinal bacterial overgrowth (SIBO)

Small intestinal bacterial overgrowth is a condition characterized by overgrowth of microbes in the small intestine. As a result, fermentation of food begins before it has been thoroughly digested and absorbed, which can lead to gas formation (Yamini 2010; Pyleris 2012). SIBO is more common in people with motility disturbances, low stomach acid production, and bowel obstruction (Yamini 2010). The prevalence of small intestinal bacterial overgrowth in IBS varies across studies, but estimates range from about 20-84% (Reddymasu 2010; Yakoob 2011; Sachdeva 2011).

Medications that may contribute to IBS development

Certain medications may contribute to the development of IBS (Keszthelyi 2012). Proton pump inhibitors (eg, omeprazole [Prilosec®]), which are used to treat heartburn, can alter intestinal barrier function, affect intestinal microflora, and are known to have a positive association with IBS (Keszthelyi 2012). Similarly, many common analgesics, such as non-steroidal anti-inflammatory drugs (NSAIDs), are known to damage the intestinal epithelium, an important barrier against harmful substances. This tissue damage may compromise intestinal permeability (Kerckhoffs 2010). Although broad-spectrum antibiotics are designed to target systemic infections, antibiotics are known to alter the colonic flora (Villarreal 2012). Indeed, a study showed that the use of broad-spectrum antibiotics, particularly macrolides (eg, erythromycin) or tetracyclines (eg, tetracycline, doxycycline), was associated with IBS development (Villarreal 2012).

Food sensitivities

Food sensitivities may have a role in IBS.  Please see the Dietary Considerations section of this protocol for an exploration of this topic.

Gluten sensitivity
Gluten is a protein component of some grains, especially wheat. Sensitivity to gluten is common and is associated with a spectrum of symptoms ranging in severity from minor skin conditions to severe gastrointestinal compromise in the case of celiac disease (Pietzak 2012; Di Sabatino 2012; Lundin 2012; Usai 2007). Some evidence suggests gluten sensitivity potentially contributes to IBS symptoms (Verdu 2009; Pietzak 2012). Although evidence is not yet strong enough to support a recommendation that all IBS patients avoid gluten, findings from at least one study indicate that using a blood test to detect immunoglobulin G (IgG) antibodies against components of wheat may help identify patients with diarrhea-predominant IBS who are likely to respond positively to a gluten-free diet (Wahnschaffe 2007).

Post-infectious IBS

Some cases of IBS arise following a gastrointestinal infection, usually with a bacterial or parasitic pathogen (Qin 2011). This is called post-infectious IBS, or PI-IBS, and occurs in up to about 30% of individuals who contract an acute gastrointestinal infection (Ghoshal 2011; Thabane 2009). Symptoms of PI-IBS typically resemble IBS-D (Ghoshal 2011). Irritable bowel symptoms are thought to arise following enteric infection due to inflammatory damage to the gut epithelium, which increases intestinal permeability; alterations in intestinal flora may also contribute (Serghini 2012; Pallotti 2011; Thabane 2009). Some estimates suggest as many as one-third of all IBS cases may arise post-infection (Schwille-Kiuntke 2011). 

Hormone fluctuations

Some evidence suggests a potential role for sex hormone imbalance(s) in IBS. For example, women often experience worsening of IBS symptoms near menstruation, which coincides with natural changes in sex hormone levels (Heitkemper 2009; Jane 2011). One study found that women with IBS have generally lower estradiol levels than their healthy counterparts (Cui 2006). However, postmenopausal women have fewer symptoms compared to women who are still menstruating (NDDIC 2012).

4 Symptoms and Diagnosis

The cardinal symptom of IBS is abdominal pain that is relieved with defecation and associated with a change in stool frequency or appearance (Di Palma 2012). Pain or discomfort associated with IBS typically “flares” for 2-4 days intermittently. Other symptoms not directly associated with the GI tract have been reported in some IBS patients, including headache, backache, and lethargy. People with IBS frequently experience symptoms for years after diagnosis; however, IBS does not increase risk for more serious conditions like colon cancer (Spiller 2007).

Subcategories of IBS include constipation-predominant (IBS-C) and diarrhea-predominant (IBS-D), with the former associated with fewer than 3 bowel movements per week and the latter associated with more than 3 bowel movements per day (Mearin 2012).

Diagnosing IBS is complex and often involves multiple tests to rule out several other diseases that may be associated with IBS-like symptoms such as hyperthyroidism, celiac disease, lactose or fructose malabsorption, IBD, microscopic colitis, colon cancer and/or pancreatic cancer (Torpy 2011; Mearin 2012; Spiegel 2010). A complete blood count and blood chemistry panel may be ordered as well to assess for anemia or other abnormalities (Torpy 2011).

The Rome III criteria have been developed in order to help facilitate accurate diagnosis of IBS (Dang 2012; Thompson 2006; Ferri 2012).

According to the Rome III criteria, a diagnosis of IBS requires recurrent abdominal pain or discomfort at least 3 days per month during the past 3 months associated with 2 or more of the following (Longstreth 2006; Lee 2012; Ferri 2012): 

  1. improvement with defecation
  2. onset associated with a change in stool frequency
  3. onset associated with a change in stool appearance

5 Conventional Treatment

Irritable bowel syndrome treatment aims to alleviate predominant symptoms, such as diarrhea, constipation, or abdominal cramping (Lee 2012).

Bulking agents

Bulking agents (ie, dietary fiber) are frequently used to treat both subtypes of IBS. Insoluble fiber facilitates defecation by reducing transit time, or the time it takes for the remains of ingested food to be excreted. While defecation generally alleviates IBS symptoms, a comprehensive review found conflicting effects of bulking agents on IBS severity (Trinkley 2011; Ruepert 2011). A potential side effect of fiber supplements is bloating (Mayer 2008), which can exacerbate certain IBS types who have difficulty evacuating their bowels.


Laxatives and stool softeners are commonly used to treat IBS-C (Trinkley 2011; Mayer 2008). These treatments typically provide rapid relief, but are not recommended for long-term use as they can cause electrolyte imbalances by enhancing the excretion of fluids (Roerig 2010). The most common laxatives work by osmosis, that is, they draw fluid into the intestine producing softer stools that are easier to pass. Polyethylene glycol (MiraLAX®) is one of the most studied laxatives; it has been shown to be superior to lactulose (another osmotic laxative) (Attar 1999). Lubiprostone (Amitiza®) is a prostaglandin E1 analog that draws fluid into the intestine by directly acting on the ClC2 chloride receptor. Lubiprostone is indicated for IBS-C in the United States (Trinkley 2011; Barish 2010). Lubiprostone acts quickly to facilitate defecation, relieve discomfort, and resolve abdominal pain (Lacy 2008; Ambizas 2007).

Antispasmodic medications

Antispasmodics relax the smooth muscle of the lower GI tract and may be helpful in IBS, especially for abdominal pain; although more data from high quality randomized controlled trials are needed to thoroughly assess their effectiveness (Ruepert 2011; Trinkley 2011; Mayer 2008). In studies conducted in Europe, alverine (Spasmonyl®), which blocks signaling through a specific serotonin receptor called 5-HT1a, was effective at relieving abdominal pain and discomfort in IBS patients when combined with the oral anti-foaming agent simethicone (Gas-X®) (Wittmann 2010). However, alverine was shown to be ineffective when used alone (Mitchell 2002). Antagonists of either muscarinic acetylcholine or 5-HT1a receptors exert direct antispasmodic effects, whereas simethicone reduces gas/flatulence and is not an antispasmodic (Wittmann 2010). Propantheline (Probanthine™) is an anticholinergic antispasmodic medication used to treat IBS (PubMed Health 2011).


Centrally acting
Antidepressants are another class of therapeutic agents that can be used in IBS treatment (Trinkley 2011). They do not address the underlying condition, but instead reduce feelings of discomfort. These drugs have demonstrated a modest degree of success (Ruepert 2011). The selective serotonin reuptake inhibitor (SSRI) paroxetine (Paxil®) has shown some benefits (Masand 2009), although results with another SSRI, citalopram (Celexa®), suggest that efficacy might be limited to IBS sufferers who are also clinically depressed (Ladabaum 2010). The dual serotonin norepinephrine reuptake inhibitor (SNRI) duloxetine (Cymbalta®), on the other hand, is efficacious in non-depressed IBS patients, but is typically limited to IBS-D since constipation is a potential side effect (Brennan 2009). Tricyclic antidepressant drugs like amitriptyline inhibit peristalsis and can markedly worsen constipation-predominant IBS.

Locally acting
Alosetron (Lotronex®), which blocks an intestinal serotonin receptor called the 5-HT3 receptor, is used to treat IBS-D (Cremonini 2012; Spiller 2007). One randomized clinical trial in women with severe IBS-D showed significant beneficial effects of alosetron vs. placebo, whereby every measured aspect of quality of life improved (eg, emotional, mental health, sleep, energy, etc.) and workplace productivity increased (Cremonini 2012). However, alosetron may cause significant side effects including severe constipation and loss of blood flow to the colon (PubMed Health 2010; Gallo-Torres 2006). Alosetron is indicated for use in women with severe IBS-Diarrhea who have not responded to other therapies (Mayer 2008) and not IBS of the constipation type.

Other treatment considerations

Small intestinal bacterial overgrowth
Evidence suggests that small intestinal bacterial overgrowth (SIBO) may contribute to IBS symptoms in some patients (Yamini 2010; Lee 2006). The gold standard for diagnosing SIBO is microbial investigation of fluids collected from the small intestine. Other non-invasive testing such as hydrogen and methane breath tests are more commonly used. Antibiotics are a mainstay in SIBO therapy however, probiotics (see below) are becoming an increasingly appreciated option (Quigley 2006; Bures 2010).

Balancing hormones

Premenopausal women often experience IBS symptom exacerbation around menstruation, which may be related to fluctuations in sex hormone levels (Jane 2011; Heitkemper 2009). Using blood testing to assess hormone levels and, if necessary, working with an experienced, integrative physician to appropriately balance hormone levels may represent a potential solution, though studies have yet to test this hypothesis.

6 New and Emerging Therapies


Linaclotide (Linzess®) activates a receptor in cells on the intestinal surface called the guanylate cyclase 2C receptor, which stimulates intestinal fluid secretion and softens the stool making it easier to pass. Linaclotide is effective in attenuating IBS-C, chronic constipation, and abdominal discomfort (Lembo 2011). Linaclotide was approved by the Food and Drug Administration (FDA) for the treatment of IBS-C in August 2012, an indication shared by only one other drug (Lubiprostone [Amitiza®]). Linaclotide and lubiprostone treat both constipation and pain, whereas traditional laxatives do little to relieve abdominal pain (Gordon 2012). In two large randomized clinical trials, linaclotide safely and effectively treated bowel and abdominal symptoms associated with chronic constipation (Lembo 2011).


Some evidence implicates low-level inflammation and immune system activation in IBS (Hauser 2012; Camilleri 2012). Although the specific contributions of inflammation to IBS symptoms are not fully understood, the aspirin-like anti-inflammatory drug mesalazine (also known as mesalamine and 5-aminosalycylic acid [5-ASA]), which is used in the treatment of inflammatory bowel disease (Klotz 2012), has successfully relieved IBS symptoms in clinical trials (Bafutto 2011). In one trial, 360 subjects with varying types of IBS were treated with 500 mg of mesalazine 4 times daily or standard therapy for 28 days. Mesalazine treatment led to significant reductions in pain and symptom duration in most IBS subtypes. In addition, the treatment normalized stool patterns among subjects with IBS-D and lessened infiltration of immune cells into bowel mucosa (Dorofeyev 2011). In an earlier proof-of-concept study conducted on 20 IBS patients, treatment with 800 mg mesalazine 3 times daily for 8 weeks led to marked reductions in the number of immune cells present upon examination of colonic biopsy specimens and improved subjects’ general well-being (Corinaldesi 2009).

7 Dietary Considerations

Dietary considerations such as reducing daily intake of caffeine and fatty foods may benefit individuals with IBS (Lee 2012). Individuals with IBS are often aware of some foods that exacerbate symptoms; thus, they may be able to improve symptoms by avoiding those foods (Torpy 2011). The following specific diets may help manage IBS symptoms. Each involves the selective exclusion of one or more types of food.

FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols)

A low FODMAP diet is based on the hypothesis that impaired carbohydrate absorption allows excess undigested carbohydrates to reach the lower GI tract (large intestine). There, undigested carbohydrates stimulate the growth of pathogenic microbes, leading to excess gas, diarrhea, and constipation (Ostgaard 2012). Theoretically, the restriction of fermentable foodstuffs deprives the dysbiotic gut flora of their energy source and results in decreased symptoms.

Foods typically avoided on a low FODMAP diet include: fructo-oligosaccharides (eg, wheat, rye, onions, garlic, artichokes), galacto-oligosaccharides (eg, legumes), lactose (eg, milk), fructose (eg, honey, apples, pears, watermelon, mango), sorbitol (eg, apples, pears, stone fruits, sugar-free mints/gums), and mannitol (eg, mushrooms, cauliflower, sugar-free mints/gums). In one study, IBS sufferers assigned to a low FODMAP diet experienced significant improvement in their symptom response (ie, bloating, abdominal pain, and flatulence) relative to a standard diet group (Barrett 2012; Staudacher 2011). These results are supported by a later study showing that IBS patients who were guided to eat a low FODMAP diet experienced a significant decrease in abdominal pain (Ostgaard 2012).


While a gluten-free diet is required for patients with celiac disease, there is a wide spectrum of non-celiac gluten sensitivities that present like IBS (Volta 2012). Gluten is found in grains (eg, wheat, barley, rye), breads, pasta, etc. Similar to the gluten-free diet, the low FODMAP diet also restricts gluten. Both diets are used to manage food sensitivities, suggesting that gluten sensitivity might be a more common contributor to IBS symptoms than previously thought (Carroccio 2012). In one double-blind, randomized, placebo-controlled study of IBS sufferers who specifically did not have celiac disease, addition of gluten worsened abdominal pain, bloating, fatigue, stool consistency, and overall symptoms of IBS (Biesiekierski 2011).

Food Sensitivities and IBS

Many features of IBS are similar to food sensitivities. A food allergy or food sensitivity is an inappropriate immune response to one or more components of the diet. Following ingestion, the immune system “attacks” particles of the problematic food(s). This “attack” is mediated by antibodies, which are components of the immune system that normally identify pathogens and trigger an immune response. In the case of food sensitivities or food allergies, antibodies mark certain food particles as pathogens and initiate a wider immune response that can lead to tissue inflammation and/or dysfunction.

Conventionally recognized “food allergies” are primarily mediated by two specific types of antibodies: immunoglobulin E (IgE) and immunoglobulin A (IgA). However, evidence suggests that “food sensitivities,” which are triggered primarily by the immunoglobulin G (IgG) antibody, may contribute to intestinal disorders as well, although mainstream medicine typically refutes this hypothesis. The reduction in IBS symptoms seen following the elimination of IgG-positive foods attests to the viability of this theory (Drisko 2006).

In one study, IBS patients were tested for IgG antibodies against a variety of foods, including chicken, wheat, soybeans, and rice (Atkinson 2004). They were then assigned to diets that excluded the foods to which they were IgG positive. In almost every case, this resulted in a significant improvement, which was reversed when the troublesome foods were re-introduced (Atkinson 2004). Similar findings were discovered in a 2012 study that demonstrated the existence of an IgG-mediated food sensitivity (Carroccio 2012). In this study, IgE testing was important to exclude food allergy, whereas IgG testing was important to diagnose food sensitivity. Taken together, these findings suggest that specific elimination diets may be successful and that IgG food sensitivity testing may help identify foods that contribute to IBS (Shanahan 2005).

8 Lifestyle Considerations

Stress Reduction

Stress associated with early life adverse events is implicated in the etiology of IBS (Bradford 2012); about 50% of individuals who seek IBS treatment have depression or anxiety (Spiller 2007). This relationship appears to be bidirectional, meaning that IBS may cause stress, and stress may contribute to IBS symptoms. This cycle may be partially attributed to enhanced sympathetic nervous system (“fight or flight”) signaling in IBS patients relative to healthy controls (Berman 2009).

IBS symptoms appear to respond positively to stress reduction. In one study, a meditation-based intervention known as mindfulness-based stress reduction (MBSR) reduced the severity of IBS and stress symptoms in IBS patients, although improvements in mood and quality of life were similar to those of a control group of IBS patients who were placed on a waiting list for MBSR (Zernicke 2012). Furthermore, psychological therapies — including cognitive therapy, dynamic psychotherapy, and hypnotherapy — have been deemed highly effective in relieving global symptoms of IBS by the American College of Gastroenterology Task Force on IBS (Brandt 2009).


Exercise also appears to be beneficial for IBS patients. In one study, subjects who engaged in 20–60 minutes of moderate to vigorous physical activity 3 to 5 days per week experienced a marked improvement in quality of life that was associated with reduced IBS severity (Johannesson 2011).


Some clinical trials suggest that acupuncture may alleviate IBS symptoms (Stuardi 2012; Macpherson 2012; Shi 2011), but a 2012 comprehensive review found that evidence remains inconclusive (Manheimer 2012). Although more trials are needed, acupuncture may be a useful adjunct to conventional IBS treatment and is not likely to cause significant side effects.

9 Nutrients

Immediate Relief from Constipation-Predominant IBS

Some cases of IBS of the constipation type are caused by insufficient peristalsis, which means there is not enough colon contractile activity to completely evacuate the bowels (Grassi 2011). Instead of reverting to laxatives, there are specific nutrients that, if taken at the right time, can induce healthy colon peristaltic action without producing adverse effects.

On an empty stomach, certain nutrients will induce powerful colon peristalsis. One combination is taking several teaspoons of a buffered vitamin C powdered mix that contains in each teaspoon, 4,000 mg of vitamin C, 365 mg of potassium, and 55 mg of magnesium. The powder should be mixed in eight ounces glasses of water or the juice of a freshly squeezed grapefruit and wait for the fizzing to stop before drinking. This convenient product sold by several vitamin companies contains magnesium and potassium salts mixed with ascorbic acid which induces an evacuation of bowel contents within 30-90 minutes. Depending on the person, a few teaspoons (or, in some cases, 1 to 2 tablespoons) of this buffered vitamin C powder can produce a powerful but safe laxative effect.

Another popular approach is to use one teaspoon of an effervescent powder containing 4500 mg of ascorbic acid and 250 mg of magnesium carbonate that will evacuate the bowel within 30-90 minutes if taken on an empty stomach with several glasses of water. In either case, the dose should be adjusted individually based upon your response: if you experience diarrhea, reduce the dose.

Nutritional laxatives such as ascorbic acid mixed with magnesium and potassium salts are becoming more popular with people who have constipation that is resistant to fiber therapies.

Peppermint oil/ Caraway oil

Peppermint oil is a natural antispasmodic. In one study, an enterically-coated preparation of 225 mg peppermint oil taken twice daily was shown to reduce all IBS symptoms by over 50% in three-fourths of the patients, whereas only 38% of the placebo group improved (Cappello 2007). In another well-designed study, 187 mg of a similar peppermint oil product taken 3 times daily for 8 weeks led to a significant improvement over placebo with regard to abdominal discomfort, abdominal pain, and quality of life, but not in terms of diarrhea, constipation, or bloating (Merat 2010). IBS patients treated with peppermint oil in yet another study reported benefits including decreased abdominal pain, less bloating and flatulence, decreased stomach growling, reduced stool frequency, and improved stool consistency (Liu 1997).

In a clinical study using a fixed combination of peppermint and caraway oil, 45 patients with non-ulcer dyspepsia, the majority of whom had IBS, were studied in a double-blind, placebo-controlled trial. The test group took one enteric-coated capsule 3 times daily for 4 weeks. While all patients complained of moderate to severe pain before treatment, 42% of the patients in the test group were pain-free 2 weeks after taking the combination therapy. Only one patient in the placebo group reported freedom from pain. After 4 weeks of treatment, 63% of those that received the combination formula were pain-free compared to 25% in the placebo group; 89% showed improvement in the combination formula group versus 45% in the placebo group (May 1996).


Probiotics are microorganisms that may provide health benefits to their host when administered at sufficient levels (Ciorba 2012).

A pathogenic alteration in the gut microflora – dysbiosis – is one consistent finding associated with both IBS-D  and IBS-C, which can cause or exacerbate IBS symptoms in a variety of ways (Carroll 2012; Chassard 2012). Dysbiosis is associated with increased intestinal permeability whereby pathogens, toxins, or undigested foods that are not usually absorbed are able to pass into the bloodstream. This can trigger abdominal pain and altered bowel habits (Barbara 2012). Dysbiosis can also lead to aberrant immune system activation, resulting in the release of cytokines that increase abdominal pain perception and alter bowel habits (Barbara 2012).

Dysbiosis associated with IBS produces an abnormally high amount of gas in response to certain foods, particularly those high in fermentable carbohydrates (Ong 2010). This results in an increase in abdominal bloating, abdominal pain, and flatulence that is reversed by avoiding those foods (Staudacher 2011). Probiotic supplementation may help rebalance intestinal flora and alleviate IBS symptoms.

A particularly important type of probiotic – bifidobacteria – is found in reduced quantities in the GI tracts of both IBS-C (Chassard 2012) and IBS-D (Duboc 2012) sufferers relative to healthy individuals (Balsari 1982). In one study, probiotic B. infantis 35624, in a dose of 10 billion colony forming units (CFUs), significantly improved abdominal pain/discomfort, abdominal bloating/distension, and difficulty with bowel movements in women with IBS after only 4 weeks (O'Mahony 2005). In a randomized clinical trial, IBS patients treated with 1 billion CFUs of bifidobacteria (a relatively low dose) experienced significant improvements in abdominal discomfort, bloating, and urgency relative to those who received placebo (Guglielmetti 2011). This treatment resulted in a significant improvement in quality of life and mental health (Guglielmetti 2011).

Another more robust finding supporting probiotic use in IBS comes from a study of the probiotic L. plantarum DSM 9843. In this study, 20 billion CFUs were administered daily for 4 weeks to IBS sufferers. Flatulence resolved rapidly, and improvements in overall GI function remained long after supplementation was discontinued (Nobaek 2000).

Collectively, these data suggest probiotics are effective in treating IBS, with strains of bifidobacteria being more favorable than lactobacilli, as lactobacilli are actually increased in certain populations with SIBO (Bouhnik 1999) and IBS (Tana 2010; Carroll 2010), correlating with worse symptoms (Rajilic-Stojanovic 2011).

Saccharomyces cerevisiae (S. cerevisiae) is a probiotic yeast that has a long history of use in fermented foods, including wine and sourdough (Hatoum 2012; De Vuyst 2014), and may be useful as a supplement in people with IBS. In a controlled trial, 179 people with IBS were treated with either 500 mg (4 billion CFUs) of S. cerevisiae per day or placebo. After eight weeks, 63% of subjects receiving S. cerevisiae reported reductions in abdominal pain and discomfort, while only 47% of subjects receiving placebo reported reductions in these symptoms (Pineton de Chambrun 2015). Findings from laboratory and animal studies suggest S. cerevisiae may exert its beneficial probiotic effects by protecting against intestinal pathogens, preventing intestinal hyperpermeability, and modulating the inflammatory response (Etienne-Mesmin 2011; Generoso 2010; Sivignon 2015). While S. cerevisiae has been shown to be safe in general, there are case reports of S. cerevisiae infections in susceptible people (Pillai 2014; Santino 2014); therefore, this probiotic should be used under medical supervision in immunocompromised individuals or those with chronic disease.


Artichoke leaf has been used since Roman times as a traditional medicine that supports digestive function. It has been shown to promote the production of bile that helps digest dietary fats and reduce spasms and flatulence. In one study, 2 capsules of 320 mg artichoke leaf extract taken 3 times daily almost completely eliminated abdominal pain, cramps, bloating, flatulence, and constipation in a population of IBS sufferers who also exhibited nonspecific GI discomfort or dyspeptic syndrome (Walker 2001). This was later confirmed and accompanied by a significantly improved quality of life in artichoke leaf extract-supplemented patients with functional dyspepsia (Holtmann 2003). In another study, consumption of 320 or 640 mg of artichoke leaf extract daily for 2 months significantly attenuated IBS symptoms and improved quality of life (Bundy 2004b).


Melatonin is a multifunctional hormone that exhibits a variety of beneficial effects in gastrointestinal disorders independent of its more widely known effects on sleep (Chen 2011). In one study of IBS patients with sleep disturbances, 3 mg of melatonin taken prior to bedtime for 2 weeks significantly decreased abdominal pain and rectal sensitivity (Song 2005). These findings were confirmed in a larger double-blind, placebo-controlled crossover study in which 3 mg of melatonin reduced abdominal pain and bloating in women with IBS (Lu 2005). In a study that examined a wider array of symptoms, besides improving bowel function, melatonin was also associated with a marked reduction in lethargy in a group of IBS sufferers (Saha 2007).

Perilla Leaf Extract

Perilla frutescens is a plant in the mint family that is native to East Asia. Its leaves are rich in polyphenols and, in addition to being a flavorful and aromatic ingredient in many traditional foods, perilla leaf has been demonstrated to be of benefit in allergic, respiratory, and digestive ailments (Asif 2012). In a randomized controlled trial, 50 participants with gastrointestinal discomfort and reduced bowel movement frequency were treated with ether perilla extract, 150 mg twice daily, or placebo for four weeks. All gastrointestinal symptoms, including abdominal discomfort, flatulence, rumbling, fullness, and bloating, improved significantly in the perilla group. For bloating, the positive response in the perilla group was 46% greater than in those receiving placebo (Buchwald-Werner 2014).

Perilla may have several modes of action that contribute to its beneficial effects for digestive symptoms. Preclinical studies indicate perilla stimulates motility of the intestinal tract (Koezuka 1985) and may relax intestinal muscle spasms (Verspohl 2013). Other studies found perilla extract can inhibit the inflammatory response generally (Chen 2015; Lee, Han 2012; Oh 2011) and specifically in the large intestine in mice (Urushima 2015). In addition to preventing a stress-induced inflammatory response, an essential oil extract of perilla prevented depression-related behaviors in chronically stressed mice (Ji 2014). Another study also noted a reduction in signs of stress-induced depression and a reversal of stress-induced changes in brain metabolism in mice treated with perilla essential oil. In this study, perilla extract compared favorably to fluoxetine (Prozac) (Yi 2013). Stress, anxiety, and depression are known to be associated with changes in pain sensitivity, gastrointestinal motility, and intestinal permeability via a complex network that connects the gastrointestinal tract, brain, immune system, and microbiota (Moloney 2016). Thus, available evidence suggests perilla extract may be an especially promising treatment option for individuals with IBS.

Additional support

In one large non-placebo controlled trial, consumption of 72 or 144 mg Curcuma longa extract daily for 8 weeks significantly reduced IBS prevalence and improved quality of life (Bundy 2004a).

Saccharomyces boulardii
The probiotic yeast Saccharomyces boulardii was shown in one study to improve quality of life measures among subjects with IBS after 4 weeks of treatment (Choi 2011).

Stress-modifying natural therapies
Several natural compounds, including adaptogenic herbs (eg, Rhodiola, Bacopa, Holy Basil, Ashwagandha and Cordyceps) and stress-response-modifying nutrients such as phosphatidylserine,may benefit IBS sufferers by mitigating stress.  

For example, Rhodiola rosea is effective in alleviating a variety of psychological conditions, including irritability, anxiety, and loss of zest for life (Edwards 2012). As such, it might offer relief to IBS sufferers, although this has yet to be empirically tested. Similarly, some IBS patients exhibited altered dynamics of the stress hormone cortisol (Suarez-Hitz 2012), which may be corrected by an omega-3 fatty acid-enriched phosphatidylserine supplement (Hellhammer 2012; Starks 2008; Noreen 2010).

Research on Bacopa monnieri indicates that it has adaptogenic effects and can significantly decrease stress-related anxiety (Tubaki 2012; Singh 1980). Bacopa (in combination with another herb) was found to be particularly beneficial in IBS-D in a 6 week randomized, controlled trial (Yadav 1989).  

More stress-reduction strategies are discussed in Life Extension’s Stress Management protocol.

Disclaimer and Safety Information

This information (and any accompanying material) is not intended to replace the attention or advice of a physician or other qualified health care professional. Anyone who wishes to embark on any dietary, drug, exercise, or other lifestyle change intended to prevent or treat a specific disease or condition should first consult with and seek clearance from a physician or other qualified health care professional. Pregnant women in particular should seek the advice of a physician before using any protocol listed on this website. The protocols described on this website are for adults only, unless otherwise specified. Product labels may contain important safety information and the most recent product information provided by the product manufacturers should be carefully reviewed prior to use to verify the dose, administration, and contraindications. National, state, and local laws may vary regarding the use and application of many of the therapies discussed. The reader assumes the risk of any injuries. The authors and publishers, their affiliates and assigns are not liable for any injury and/or damage to persons arising from this protocol and expressly disclaim responsibility for any adverse effects resulting from the use of the information contained herein.

The protocols raise many issues that are subject to change as new data emerge. None of our suggested protocol regimens can guarantee health benefits. Life Extension has not performed independent verification of the data contained in the referenced materials, and expressly disclaims responsibility for any error in the literature.

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