Irritable bowel syndrome (IBS, motility disorder, functional bowel disorder)

Irritable Bowel Syndrome (IBS) is thought to be due to inappropriate muscular activity within the bowel.  The bowel wall contains layers of muscle which enable it to push food contents on downward.  This is usually a well-coordinated, wave-like muscle action called ‘peristalsis’.  If the muscle activity becomes discoordinated, a variety of symptoms may occur, including cramps, bloating, diarrhea, and constipation.  Some patients seem to have more of a diarrhea problem while others have predominantly a constipation problem.  Still others swing from diarrhea to constipation.  Sometimes the food may pass down and out very quickly and may appear not to have been digested completely.  A common symptom is the urge to have a bowel movement shortly after eating, or, in fact, during a meal.  Young people with this disorder often complain that they find dating difficult because they will usually have to get up to go to the washroom to have a bowel movement during the meal and this embarrasses them.

Although IBS can be a terrible nuisance, it is a benign disorder.  Investigations may be done to rule out more serious problems like inflammatory bowel disease, infection, celiac disease, etc.  Stool cultures should show no infection and no significant amounts of white blood cells (these findings would indicate a possible infectious or inflammatory disorder rather than a simple muscle coordination problem).

Many patients with what is thought to be IBS will improve if they eliminate milk products from their diet since there may be an element of lactose intolerance in that individual.  A higher fiber diet and a fiber supplement like Metamucil (in small doses) may reduce symptoms in some, although not in all.  In fact, some patents may do better on a low fiber diet so it may be worth experimenting with.  One of the many probiotics on the market may be useful in some people.  There are a limited number of medications that can be tried.  Their effectiveness varies.

© Pezim Clinic, Vancouver, British Columbia, Canada