The question: What foods should I avoid if I have irritable bowel syndrome?
The answer: Altering your diet can definitely help reduce or eliminate the uncomfortable, and sometimes painful, symptoms of irritable bowel syndrome (IBS). Which foods you should avoid – and which ones you should eat more of – depends on the IBS symptoms you are experiencing.
Doctors refer to IBS as a functional disorder, since there is no sign of any abnormality when a person's large bowel, or colon, is examined. It's thought that symptoms result from overly reactive and/or extra sensitive nerves that control muscles in the bowel.
Most people with IBS experience either diarrhea (IBS-D or diarrhea-predominant) or constipation (IBS-C or constipation-predominant), but some people alternate between diarrhea and constipation (IBS-A). People with IBS may also experience abdominal pain and bloating.
Start by assessing your diet for certain foods that set off or worsen your symptoms. I advise my clients to keep a food and symptom journal to determine if any foods bother them. In many people with IBS-D, fatty foods, caffeine, chocolate, alcoholic beverages, carbonated beverages, sorbitol (an artificial sweetener used in sugar-free gum and diet candies) and fructose (the simple sugar found in honey and many fruits) can worsen cramping and diarrhea.
People with IBS-C should include good sources of insoluble fibre such as wheat bran, 100 per cent bran cereal, whole grain cereals, fruits and vegetables in their daily diet to promote regular laxation. If you have IBS-D, it’s best to consume more soluble fibre – the type in oat bran, barley, psyllium husks, citrus fruit and legumes – which helps bind intestinal contents.
Increase your fibre intake gradually over a period of two to three weeks. Drink at least 9 cups (2.2 litres) of water each day. Fibre needs to absorb water so it can function effectively in the body.
Another dietary approach to treat IBS is to follow the FODMAP diet for one to two weeks. FODMAP stands for the names of five fermentable carbohydrates found in foods that have been shown to increase abdominal pain, gas and bloating. Foods high in FODMAPS include certain fruits and vegetables, rye, wheat, milk, yogurt, legumes, fructose and sugar alcohols.
If high FODMAP foods cause symptoms, eliminating them can cause relief within days. After the elimination period, foods are added back gradually, one at a time, to determine the foods you can tolerate with the goal of finding the most varied diet possible. I strongly recommend people work with a registered dietitian knowledgeable about the FODMAP approach.
Taking a supplement of probiotics, or so-called "friendly" bacteria, may also help treat IBS. It's been suggested that people with IBS don't have enough friendly bacteria in their digestive tract. A few studies, but not all, suggest that consuming foods or supplements that contain Bifidobacteria reduces abdominal pain and bloating in people with IBS.
Finally, don't skip meals. Eat well-balanced meals at the same time each day to promote regular bowel function. People with IBS-D may find eating smaller meals more frequently reduces symptoms.
Leslie Beck is a registered dietitian.