Irritable bowel syndrome (IBS) and nutrition

Digestive system

What is irritable bowel syndrome?

Irritable bowel syndrome (IBS) is a chronic condition of the large intestine (colon). The cause of IBS is unknown. In IBS, food moves through the colon too slowly, quickly or unpredictably. As a result, water absorption by the colon is disrupted causing diarrhea or constipation.

Stomach infections, stress, some foods and medicines can trigger symptoms of IBS, but do not cause it.

Symptoms of IBS vary

Symptoms can flare-up, disappear and change over time. Common symptoms include:

• stomach pain or discomfort (cramping)
• bloating
• a changed need to go to the bathroom: either more often or less often
• change in consistency of stools (diarrhea, constipation)
• symptom relief after bowel movements

IBS is not known to lead to other serious health problems. IBS can affect mental and social well-being if not well managed.

Common IBS triggers

Some foods can make IBS symptoms worse by making the bowels over sensitive. Foods that can do this may include:

• foods high in insoluble fibre (raw fruits and vegetables, whole grains, bran, legumes)
• dairy products
• nuts, seeds and raisins
• chocolate
• spicy food
• coffee or other caffeinated beverages
• carbonated beverages
• alcohol
• artificial sweeteners (aspartame, sorbitol, sucralose, xylitol, maltitol)

Other factors may increase IBS symptoms by over-stimulating the bowels. These may include:

• high-fat or very low-fat diet
• eating large meals.
  

No specific tests to diagnose IBS

Diagnosing IBS may not be simple because the colon often looks normal. Your family doctor may refer you to a gastroenterologist to confirm diagnosis of IBS. Often, tests eliminate the possibility of other intestinal disease. IBS may run in families.

IBS and IBD are not the same thing

IBD stands for Inflammatory Bowel Disease. Although some symptoms between IBS and IBD are the same, IBD has other significant symptoms that make it different from IBS. IBD is often diagnosed with much more confidence and has specific treatments. It is common to misdiagnose IBD as IBS without a thorough examination.

Managing IBS with life-style and diet changes

There is no cure for IBS, but symptoms can be managed. How IBS symptoms are best managed varies from person to person. You may have to try different things to discover what works for you.

Lifestyle changes

• Get enough sleep and exercise
• Avoid stress as much as possible
• Avoid eating on-the-run or skipping meals

Dietary changes

• Eat small and frequent meals during the day
• Avoid large meals
• Eat meals slowly
• Eat higher protein and lower fat meals
• Eat foods with plenty of soluble fibre (oat bran, corn, legumes, beans, oranges, apples, pears, berries, ground flax seeds)
• Drink water regularly
• Avoid foods known to cause symptoms

A note on insoluble fibre

Insoluble fibre is important for regular bowel movements, but it may cause symptoms for people with IBS. Introduce it in small amounts to find out how much you can eat and stay symptom-free. Try to peel, cook, chop or puree your fruits and vegetables. This will reduce the effect of insoluble fibre on your bowels. Sources of insoluble fibre include whole grains, brown rice, rye, whole flax seeds, vegetables, fruit and corn.

Medicines to help with symptoms

Doctors can prescribe medicines for pain and for problems with bowel movements such as diarrhea, constipation, gas, and urgency. Speak to your doctor about this if you have trouble managing your symptoms.

Keep a detailed diary about food, activity, and your bowel movements

Write down the foods you eat and when; the frequency and consistency of stools; events and activities; and when your symptoms occur. This can help you and your doctor to find things to avoid and things to continue that help control symptoms of IBS.

If there are foods you suspect cause symptoms, stop eating them. If there is no symptom relief, reintroduce the foods. Stop eating one food at a time if you suspect multiple foods are causing symptoms.