If you are considering altering your diet, we recommend that you do so under the guidance of a qualified dietitian. Locate your nearest Practising Dietitian at

Your diet, what you eat and drink, can have a profound impact on how you feel. Many people feel that food affects their Crohn’s or colitis symptoms and may alter the type of food they eat or how they eat to try and manage their symptoms. Short term specific dietary or nutrition treatments can be used to treat active disease and can also help you to identify symptom triggers when your disease is in remission. In the long term however, a varied diet that includes many different foods from all of the food groups is very important. A varied diet supports optimal gut and mental health and ensures you get the nutrition your body needs to heal after a flare and respond to inflammation


Is it true that milk will make the symptoms of IBD worse?

A small number of people cannot digest the sugar (lactose) in milk and cream because they either lack the digestive enzyme lactase or their gut does not produce enough of the enzyme. Lactase enzyme is released in the upper part of the small bowel. Temporary lactose intolerance can occur during active small bowel Crohn’s disease. Lactose that is not broken down by the lactase enzyme can lead to diarrhoea, cramping, abdominal pain, gas and bloating. Many people  who are lactose intolerance can often tolerate small amounts of liquid dairy products (e.g. milk in their tea) and usually tolerate hard cheese and butter because they contain very little lactose.
Currently there is no high quality human research that shows that eating minimally processed dairy products promotes IBD inflammation. Regularly eating fermented dairy products such as yoghurt and kefir has been shown to have a positive impact on gut health and gut symptoms in people with Crohn’s and colitis. Dairy products are also high in protein and an important source of dietary calcium for most New Zealanders. If you choose not to eat dairy products choose an alternative that is calcium fortified.

Does resting the intestine help the inflammation?

There is no evidence that resting the bowel by having periods of starvation is helpful. In fact it may be more harmful as this can lead to malnutrition. The person with active IBD requires increased nutrients and energy because of the inflammation and poor digestion and absorption of nutrients. Specialised liquid formulas or tube feeds may be needed if there is obstruction in the bowel, very severe disease, or after surgery in the small bowel. It is advisable to seek guidance with nutritional requirements from the health professionals.

Is it helpful to take more or less fibre than usual in the diet?

A low fibre diet which limits the amount of ‘bulk’ in the diet is often used when there is active disease in the large bowel or terminal ileum, to help control symptoms of diarrhoea, bloating and abdominal cramping. As discussed below, most people with IBD can eat a normal or near-normal diet without making diarrhoea or pain worse. The usefulness of the strict, traditional, “low residue” diet is now seriously questioned, though it is recognised that an excess of fruit can make diarrhoea worse, just as it can cause diarrhoea in healthy people. For this reason, most doctors advise their patients to take a normal nutritious diet unless particular foods appear to cause unpleasant symptoms.
For people with Crohn’s disease with small bowel strictures (narrowing), it is advisable to reduce high fibre foods and those which may cause blockages, and abdominal cramping. Discuss this with your dietician.

Is alcohol harmful?

There is no evidence that alcohol taken in moderation makes the inflammation worse. Some healthy people notice bowel looseness after certain wines or beer, and people with IBD who notice the same thing will naturally avoid the types of alcohol that upset them. People on medication for their IBD and associated problems should consult their doctor or pharmacist to ensure that alcohol intake doesn’t interfere with the metabolism of their medication or cause additional side effects.

Do particular foods aggravate diarrhoea?

Watery frequent bowel motions are due to failure of the small intestine and/or colon to absorb fluid because the lining is inflamed and does not absorb fluids or nutrients properly. An excess of fruit or onions in some people, beer, or very spicy or fatty foods, may give healthy people diarrhoea. Such foods may aggravate the diarrhoea in people with IBD, but it is doubtful if any of them do harm. It seems sensible for people to avoid foods that they know cause them diarrhoea, but apart from this they should eat normally. When the capacity of the small intestine to absorb fat is impaired, even a normal amount of fat in the diet may cause diarrhoea. Such people may benefit from restriction of excess fat in the diet.
Many people with ulcerative colitis cannot wait when they feel the urge to go to the lavatory, regardless of whether the stool is liquid or solid. This symptom is generally due to sensitivity of the inflamed rectum and there is no evidence that a change of diet influences this sense of urgency, except in so far as the number of stools can be reduced, as already described.

Do particular foods cause pain?

Abdominal cramps may occur when there is a narrowing of the intestine so that the intestinal muscle has to contract forcibly to push the contents through the narrowed area. In this situation, lumps of indigestible food such as gristle, fibrous vegetables, orange pith, dried fruits, mushrooms or nuts may aggravate the pain because a lump of food lodges at the site of narrowing and the intestinal muscle contracts very strongly to push it through. When one or more narrowed areas of intestine are present, as may happen in Crohn’s disease, pain may be relieved by avoiding large meals and by leaving out these indigestible items of food, and chewing all food to a puree in the mouth before swallowing.

Do particular foods aggravate wind?

Wind largely arises from bacterial fermentation of food residues in the colon. Failure to absorb fat or milk sugar (lactose), as already described, may lead to flatulence. This can be helped by a low-fat or low-milk diet respectively. Food such as cabbage, broccoli and onions can lead to the formation of wind in normal people and therefore should also be taken in moderation in people with IBD. If you find yourself with problematic wind after eating a particular food, you may find it best to avoid it altogether. People will react differently to foods, so it is difficult to provide specific nutritional advice for people with IBD who experience flatulence, to follow.


Diet Ideas...

For those interested in pursuing diet ideas, there is more information available now on diet possibilities that may either improve the extent of disease or your symptoms.  It is important to remember that diet benefits vary for each person and what work's for some doesn't always work for others.  But it might be the case that eating a bit more of the foods that are common recommendations of both of the two main diets talked about in the IBD space could help symptoms.


Foods that can reduce inflammation

Here is a video you can watch of Professor Lyn Fergusson's presentation to our Wellington Support group on foods that can reduce inflammation.
'You are what you eat'


Food choices low in FODMAPS can help some patients, especially if they also have irritable bowel syndrome.  The foods to eat and foods to avoid in this diet are now easily accessible on the internet;

'The Low FODMAP Diet'

'Low FODMAP Diet - DYI Beginners Guide'

'Low FODMAP Blog'





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