Diet for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a complex disorder with a wide range of symptoms, some of which may be related to diet. Poor eating habits such as skipping meals, low intake of fibre and fluid, excessive fatty food intake, sensitivity to milk and other dairy products (see lactose intolerance) and excessive caffeine and alcohol need to be addressed as a first step in helping relieve symptoms in IBS.

General dietary advice in patients with IBS

The most common dietary treatment for IBS has been, and still is, a high fibre diet. While this is still a positive recommendation for many patients, especially those who suffer from constipation, some patients will not benefit from an increase in dietary fibre, and in some the symptoms may even worsen. As with any change in diet the increase in fibre should be gradual, involve a variety of fibres and an adequate fluid intake of at least 1.5 litres per day. The major sources of fluid should be water, but dilute tea or juices may be suitable in some patients. Caffeinated drinks such as coffee, and carbonated soft drinks can aggravate symptoms and should be limited, especially in the initial stages of dietary modification.

IBS symptoms tend to be increased following large meals, particularly if the meal is high in fat, and if the meal is eaten quickly. It can be helpful to spread the food over 3 meals and 3 snacks per day. Avoid 
eating quickly and try to relax after a meal. Regular light exercise can also help reduce symptoms.

Excessive flatulence

If excessive wind is a problem then exclusion of the 'windy vegetables' including broccoli, cauliflower, cabbage and legumes including baked beans may be helpful. These may be reintroduced once the symptoms have settled. Carbonated soft drinks can also exacerbate symptoms. Like food, fluid should be spread across the day.

Some individuals with IBS may find a trial of lactose exclusion helpful. Lactose is found principally in dairy products such as milk and ice creams (see lactose free diet). Remember that these foods supply important nutrients, and reduced consumption can affect calcium intakes.

Food sensitivities

Recent studies have highlighted the possible role of food sensitivities in some IBS sufferers (1,2). This can involve the exclusion of obvious trigger foods. In complex cases an elimination diet may be necessary. This involves the exclusion of a wide range of food, followed by 'challenges' to identify the problem foods. Elimination diets are for short-term use only as they are nutritionally unbalanced. They should be supervised by a dietitian who has experience in this field. The RPAH guide 'Friendly Food' is a general guide to the elimination diet and associated recipes.

Sensible eating for IBS sufferers

Keep a food, fluid and symptoms diary to help observe the role of diet and other factors such as stress in symptoms. Check your diet against the general guidelines for a healthy diet (see other sections of this website). Maintain a high fibre diet, provided this is tolerated. Start with the basics of 3 low fat, high fibre meals and 2 -3 snacks per day. Maintain an adequate fluid intake, avoiding excessive intake of fizzy drinks and caffeine. Eat slowly and make meal times as relaxing as possible. If you are excluding foods, eliminate one food at a time, and record the results. Once symptoms have settled reintroduce the foods to maintain variety. Consider consulting a dietitian for individual advice regarding your diet and any modifications.

A typical meal plan for IBS sufferers

This meal plan provides 25 - 30 g of fibre from a variety of sources and 30 - 35 g of fat depending 
on the quantity of added margarine, oil and fat content of dairy foods.

Breakfast - a bowl of high fibre cereal such as untoasted muesli, weetbix or porridge with fresh or tinned fruit and reduced fat milk or a calcium fortified soy milk and/ or wholemeal or grain toast with minimal margarine and honey or vegemite. Tea.

Lunch - sandwiches made with wholemeal bread with low fat cheese, lean beef, tinned fish and salad. Tinned or fresh fruit with low fat yoghurt. Water, tea or diluted juice.

Main Meal - water, lean grilled chicken with lemon juice and pepper. Served with salad, boiled new potatoes and wholemeal bread.

Snacks spread throughout the day - fresh fruit, low fat yoghurt, crackers with cheese, or wholemeal crumpets with honey. Water, tea or diluted juice.

Cookbooks which are suitable for IBS sufferers

(Prices quoted are approximate and in Australian dollars)

'Find out about fibre' by Rosemary Stanton, Allen and Unwin. $6.95

'Good Gut Cookbook' by Rosemary Stanton, 2nd ed Harper Health $19.95

'Friendly Foods' by Swain, A, Soutter and Loblay, R.H, Murdoch Books.


1. Gertner D, Powell-Tuck J. Irritable bowel syndrome and food intolerance. The Practitioner, 
July 1994, Vol 238, 499 - 504.

2. Hawthorne B, Lambert S, Scott D, Scott B. Food intolerance and irritable bowel 
syndrome. Journal of Human Nutrition and Dietetics 1991, Vol 3 19 - 23.

Some links to useful information on diets:

The Victorian Healthy Eating Healthy Living program with general information on good eating and exercise habits.

Nutritionist Catherine Saxelby's site for general nutrition information, diet quizs and product information.

Nutrition facts and recipes, including information on fibre, by Rosemary Stanton. This site allows you to construct a meal plan and shopping list using healthy recipes.

Dietitians Association of Australia site with information on finding a dietitian.