Irritable Bowel Syndrome (IBS)
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):
- improvement with defecation
- onset associated with a change in stool frequency
- onset associated with a change in stool appearance