Irritable bowel syndrome (IBS) is the most common gastrointestinal disorder. IBS troubles hundreds of millions of people world-wide (Lovell et al. 2012). Although IBS is a incurable disorder, the majority of patients experience spontaneous remission over time.
IBS includes non-specific symptoms that are also present in other diseases. The recurrent symptoms vary from person to person, but typically patients have abdominal pain and cramping, bloating, distension (feeling like pregnant), and bowel problems. Some people are constipated (hard infrequent stools), others have diarrhea (loose watery frequent stools), and yet some have alternating constipation and diarrhoea. Abnormal stool frequency (>3 bowel movements per day or <3 bowel movements per week), excessive straining during defecation, flatulence, urgency (having to rush to the toilet), incomplete bowel movements and mucus with bowel movements are common in IBS. IBS causes the embarrassment in daily life. Gas, cramps and diarrhea can suddenly strike at any time in any place, additionally causing discomfort, stress and anxiety.
For most patients the symptoms recur on average a 1 day per week.
Many IBS patients find that their symptoms are provoked or enhanced by food or stressful situations.
Irritable bowel syndrome (IBS) is not a food allergy or an abnormality in the digestive tract, it is a heterogeneous functional disorder with overlapping non-specific symptoms that are also observed in other diseases. The variety of symptoms and of patient responses to treatment suggest that there are multiple underlying causes of IBS. It is not one disease, but rather a syndrome comprised of a constellation of symptoms. It is difficult to diagnose because IBS is not associated with structural or biochemical abnormalities that are detectable with the current diagnostic tools. Doctors tend to base their diagnoses on test results, but there is no test for IBS (Sood et al. 2014). Currently, IBS diagnosis is based on symptoms and the exclusion of other possible causes.
IBS diagnosis requires the presence of recurrent abdominal pain (at least 1 day per week) together with diarrhoea or constipation for at least 3 days per month during the last 6 months (Lacy et al. 2016). Additionally, colonoscopy, gastrointestinal endoscopy, biopsies and laboratory tests are required to exclude other common gastrointestinal conditions with the symptoms similar to IBS: ulcers, coeliac disease, lactose intolerance, inflammatory bowel disease, Crohnâs disease or cancer.