by dietitian and nutritionist Alison Bencke

Note: these tips should not replace advice from your physician. Always check with your physician before making any changes to your eating habits.

If Crohn's disease sufferers follow all the advice about which "foods to avoid" found on the internet or in books, they risk nutritional deficiencies from their limited list of allowed foods. Your physician and/or a dietitian or nutritional expert recommended by your doctor should be consulted before removing foods from your diet.

Some popular diets for Crohn's disease recommend eliminating particular carbohydrates. However, the scientific evidence for this is far from conclusive. While a few sufferers report relief from symptoms on these strict regimes, the effect is often short-lived or leaves sufferers on such a restricted diet that they can not sustain it. Those continuing on these diets may risk nutrient deficiencies from the narrow choices of allowed foods.

Everyone is an individual. True food allergy usually means that if you eat even a trace of the offending food, you will have a reaction. Being food intolerant means that you can tolerate small amounts - but larger quantities trigger discomfort. For example, people who avoid milk because they are lactose intolerant (milk sugar), can often cope with small amounts of milk in foods, but will suffer discomfort if they drink a big milkshake. When Crohn's disease is very severe in the small intestine, lactose intolerance may occur. Unless your doctor has diagnosed this, there may be no reason to avoid milk as it contributes significant amount of protein, calcium and vitamins in your diet. There are lactose-free milk alternatives such as sweet acidophilus milk that are available or soy milk alternatives containing calcium.

You probably should avoid foods high in fat and added sugars, as well as the foods known to upset you. Do not cut out healthy foods that upset other Crohn's disease patients unless you have found yourself to be upset by them on more than one occasion. Your ability to heal in your gut could be compromised. It is important to understand that allergies and food intolerances vary with individuals and you may not be upset by food that others can not tolerate. Avoid missing out on favorite healthy foods unnecessarily.

Advice about foods containing fiber can be confusing depending what you read. Choose soluble fiber sources or resistant starch as they provide short chain fatty acids. Historically starch has been thought to be 100% digested to glucose in the small intestine. Research over the last few decades has found that a significant portion (about 10%) is not digested in the small intestine and passes into the large intestine where it is a substrate for bacterial fermentation. This starch is called resistant starch (RS) and many nutritionists think that it should be classified as a component of dietary fiber. The bacteria in the large intestine produce short chain fatty acids from the RS which may help maintain the health of cells lining the colon (colonocytes). These fatty acids are also absorbed into the bloodstream and may play a role in lowering blood cholesterol levels.

Fiber provides food for your good gut bacteria as discussed above. Soluble fiber is found in oats, rice, or barley bran, but not in wheat bran. Pectins, another source of fiber, are found in fruits and seeds. Plantago ovata (psyllium) is another good source of soluble fiber. Resistant starch occurs in cooked and cooled foods like potatoes and rice. The cooling process allows gels to form, which resist digestion in the small bowel. Instead, the food enters the large bowel to be digested by bacteria and form volatile fatty acids. These compounds provide fuel for the large bowel cells and may be protective in Crohn's disease. Thus, increasing the resistant starch in your diet by eating cooked and cooled potato rice and pasta may be beneficial (see the Pasta Pesto or Rice Salad recipe).

If you are sick with a flare-up, you may need a low fiber (or low residue) diet. When you are well and do not have any strictures or blockages, the best advice is to eat a well-balanced diet. Thus you may need to vary your fiber intake depending on the activity of your disease (see the Date Scones recipe which can be made with white flour).

There is some evidence to suggest that caffeine has a negative effect in Crohn's disease. Caffeine is a stimulant to the central nervous system and is recommended to be consumed in moderation. Remember to avoid anything that causes discomfort.

• Date scones
• Pasta pesto (or rice) salad
• Omega-3 potato wedges