AUSTRALIAN

ASSOCIATION Inc.

Questions and Answers about Diet and Nutrition

Prologue:

There is no evidence that dietary factors in any way cause inflammatory bowel disease. Once these diseases are established, however, attention to dietary factors may reduce symptoms and support the healing process. Improvement in nutrition also enhances the response to medications, including steroids.

1. Question: Is there a special diet for Crohn's disease and ulcerative colitis?

Answer: No. Many patients tolerate all varieties of food and require no dietary restrictions. Others, particularly when their disease is active, find a bland, low fibre diet more tolerable than a diet containing high fibre and spicy foods. The low fibre diet produces less stimulation of secretion and of contraction in the small and large intestine and this can be beneficial in the control of abdominal cramps and diarrhoea. Overall nutrition however, is more important than any consideration of the consistency of the food. If the patient has appetite for specific foods but not others, such preferences should be balanced against the possible production of symptoms such as pain, cramps and distension by high fibre foods or by spicy foods.

In special instances of Crohn's disease when an area of the small bowel is narrowed, a minimal residue diet or even a liquid diet may be necessary to minimise discomfort. Often this need be only temporary until the inflammation which causes the narrowing responds to medical treatment.

Individual experience is the most useful clinical guide in the selection of foods for each patient.

2. Question: What is a low fibre diet?

Answer: One that avoids fruits and vegetables, nuts, raisins, seeds, bran and whole grains. These foods cannot be digested as completely as others because they contain dietary fibre. Some canned or cooked fruits and vegetables can be eaten without causing gaseousness or crampiness, but notable exceptions are corn, green beans, and fruit with skin. In patients with marked narrowing of the bowel it is best to avoid even cooked fruit and vegetables, but it is possible to have fruit and vegetable juices. It may be advisable to take a multivitamin tablet daily to make up for possible deficiencies in vitamins because of the restricted diet.

3. Question: Is nutrition of special importance to patients with Crohn's disease and ulcerative colitis?

Answer: Yes, vitally so. In any chronic disease, good nutrition is one of the assets the body can utilise in its restoration to health. This is important to recognise for several reasons. Firstly, diseases such as Crohn's disease and ulcerative colitis are often associated with reduced appetite, hence good nutrition may not be easy to achieve. Secondly, chronic diseases mean chronic stress and this requires a constant replenishing of caloric energy. Thirdly, Crohn's disease and ulcerative colitis may be characterised by malabsorption and diarrhoea with associated loss of protein, fat, carbohydrates, water, minerals and vitamins. Restoration of adequate nutrition is a key principle in the medical management of inflammatory bowel disease.

4. Question: When Crohn's disease and colitis are active, what foods should be favoured?

Answer: A proper diet should be balanced and should contain daily helpings from each of the following categories: fruits and vegetables if tolerated; meat, fish or poultry and milk products, when tolerated, as sources of protein; bread, cereal and starches as sources of carbohydrate; and various fats such as margarine, butter or oils. Caloric intake should be at least 30 to 35 calories per kilogram of the ideal weight for adults, or approximately 2400 calories daily as a minimum for an average size man. Nutritional intake for children should be proportionate to proper adult diet.

5. Question: Should milk be avoided?

Answer: Many people cannot properly digest lactose, the sugar present in milk and most milk products, because they are lacking an enzyme called lactase, in the small intestine. Undigested lactose may then lead to cramps, pain, gas, diarrhoea and distension. Lactose intolerance is common enough in patients with Crohn's disease and ulcerative colitis so that patients with these diseases should be made aware of symptoms related to milk ingestion. In cases of lactose intolerance, the ingestion of milk and milk products will compound the problems patients already have and therefore, avoidance of foods containing lactose is necessary. A simple procedure, a lactose tolerance test, can be performed to confirm milk intolerance. If there is any question, milk ingestion should be limited. Milk should also be avoided when its intake is followed by distressing symptoms, even if the patient does not have lactase deficiency.

In patients who can tolerate milk, milk and milk based foods are a good source of nourishment and their use should be encouraged.

6. Question: Do any specific foods make Crohn's disease or ulcerative colitis worse?

Answer: No. While certain foods may aggravate symptoms of these diseases, there is no evidence that the inflammation of the intestine is directly affected. Any contaminated food which leads to food poisoning or dysentery will aggravate Crohn's disease and ulcerative colitis.

7. Question: Is Crohn's disease or ulcerative colitis caused by allergy to food?

Answer: No, though some people do have allergic reactions to certain foods, Crohn's disease and ulcerative colitis are not related to food allergy. Patients with these diseases may feel they are allergic to foods because they associate their symptoms with eating. However, the abdominal cramps, diarrhoea and urgency may be produced in a non-specific manner by the reaction of their inflammatory bowel disease to a host of different foods. This will depend primarily on the degree of inflammation present. This reaction is certainly not due to allergy to any specific agent and should not lead, as it sometimes does, to prolonged avoidance of a long list of food stuffs because of a presumed allergy.

8. Question: Do patients with these diseases absorb food normally?

Answer: Mostly yes. Patients with colitis alone absorb food normally since food is not absorbed in the large intestine. Patients with Crohn's disease may have problems absorbing what they eat since the small intestine is where nutrients are absorbed into the body. The problem will depend on how much ileum is diseased and whether or not the ileum has been removed. If only the last foot or two of ileum are inflamed, absorption of all nutrients except vitamin B12, which is absorbed in the terminal ileum, probably will be normal. If more than two or three feet are resected or diseased, more significant malabsorption may occur, especially of the fat in the diet. If extensive resection of the small intestine has occurred or if the proximal small intestine, the jejunum, is also inflamed, then the degree of malabsorption is much worse, and deficiencies of nutrients, minerals and vitamins are likely to result.

9. Question: In patients with malabsorption of fat, what dietary supplements are available?

Answer: If fats are poorly absorbed, not only does nutrition suffer, but diarrhoea is also worsened. Therefore, a reduction in the fat content of the diet is advised for patients with malabsorption of fat. To make up for this deficit in dietary fat, patients can substitute other caloric sources, preferably with the help of a nutritionist or physician. There are many helpful formulas currently available, some containing medium chain triglycerides (or MCT), others containing elemental diets or other predigested food supplements in liquid form.

10. Question: Should any supplemental vitamins be taken?

Answer: Vitamin B12 is absorbed in the terminal ileum, hence patients with Crohn's disease may require injections of vitamin B12 because they cannot absorb enough B12 from their diet. If patients are eating a low-fibre diet, they will often be receiving an inadequate supply of certain vitamins common in fruit and vegetables such as vitamin C and folic acid, one of the B vitamins. In the setting of chronic inflammatory disease and a suboptimal diet, it is probably worthwhile for patients to take a multivitamin preparation on a regular basis. In patients with malabsorption or a markedly shortened small bowel, the fat soluble vitamins, especially vitamin D, may be required, but only under the direction of a physician.

11. Question: Are any special minerals recommended?

Answer: In most patients with these diseases, there is no obvious lack of minerals. However, in patients with extensive small intestinal disease or resection, and in those with fat malabsorption, calcium and magnesium supplements may be necessary. Iron therapy is helpful to correct anaemia once the disease is otherwise under some control. Oral iron has the disadvantage of causing black stools and in some cases may be irritating to the gastrointestinal tract. Some oral preparations are tolerated better than others. Many gastroenterologists prefer to administer iron by injection. Children tolerate oral iron better than adults and the intramuscular preparation is less often used. As with any other medication, if there are side effects, the therapy can and should be individualised.

12. Question: Should patients with these diseases be concerned about fluid intake?

Answer: Yes. In a condition with chronic diarrhoea, the risk of dehydration is always present. If fluid intake does not keep up with the fluid loss via diarrhoea, kidney function may be affected. Patients with Crohn's disease and ulcerative colitis have an increased incidence of kidney stones, partly related to this problem. Dehydration and salt loss create a feeling of weakness. For these reasons, ample fluid should be consumed by patients with these diseases, especially in warm weather when skin losses of salt and water are a factor.

13. Question: Are kidney stones in Crohn's disease related to diet?

Answer: In patients with ileal resection of at least two feet, increased absorption of oxalate may occur. If too much oxalate is absorbed, it will react with calcium in the urine and lead to kidney stones. Dietary prevention should be instituted under these circumstances. This should include a low oxalate diet and a low fat diet. The following foods are particularly high in oxalate content and should be avoided: spinach, cocoa, beans, rhubarb, beetroots, instant coffee, diet soda and tea. Medication prescribed by a physician is also available to prevent the formation of oxalate stones and can be given to susceptible patients.

14. Question: Does nutrition affect growth?

Answer: In young patients with onset of Crohn's disease or ulcerative colitis before puberty, growth is often retarded. This is usually the result of poor food intake related to disease and symptoms. Good nutritional habits and adequate caloric intake are recommended and particularly emphasised for patients with inflammatory bowel disease. Most patients will respond to proper dietary intake and to control of the disease by means of appropriate measures, such as anti-inflammatory drugs, judicious use of steroids or at times surgical resection of an obstructed segment of diseased bowel.

15. Question: What is new in nutritional therapy that might pertain to Crohn's disease and ulcerative colitis?

Answer: Because inflammatory bowel disease seems to improve if it is put at rest, several new approaches are being evaluated. One is total nutritional support by the intravenous route, utilising a catheter placed into a large vein to facilitate the introduction of concentrated nutrient solutions. This method is called total parenteral nutrition, or hyperalimentation. This can be maintained for weeks or even months, and can be useful in allowing very active disease to subside, or to prepare patients nutritionally before subjecting them to surgery. This method is, of necessity, extensive and usually hospital based.

Another approach is the use of an elemental or astronaut diet. Such diets are in liquid form and are completely absorbed in the upper small intestine with no residue and with very little digestive effort required of the diseased bowel. Such diets consist of basic nutritional elements that do not require extensive digestion before absorption. Both of these approaches are still being evaluated and their exact role in the management of inflammatory bowel disease is still uncertain. Long term total parenteral nutrition as the sole treatment of inflammatory bowel disease is not presently favoured because of high cost and limited benefits. However, in selected patients, these approaches have been useful and have at times permitted the opportunities to initiate effective medical treatment or prepare the patient more safely for surgical resection. Total parenteral nutrition has proven to be useful more often in patients with Crohn's disease than in patients with ulcerative colitis.

When dealing with the various elemental diets or supplemental foods provided commercially, care is needed to select the most appropriate product for each patient. Thus, patients with lactase deficiency should select products that are free of lactose. Some products are overly concentrated and may induce diarrhoea, and such products should either be avoided or diluted before use. Both parenteral nutrition and elemental diets should be considered supplemental to a total therapeutic program; neither should be depended upon as a total form of medical management.

Epilogue: The purpose of this information is to provide an overall guide to physicians and patients alike, providing patients with Crohn's disease and ulcerative colitis with current knowledge about diet and the diseases. Most of this information is based upon the result of ongoing studies and the accumulation of knowledge gained in the past several years. Well designed, prospective and continuing studies are necessary to gain a greater degree of understanding of the relationship between nutrition and Crohn's disease and ulcerative colitis and to provide and substantiate more accurate answers to the questions posed here.

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Australian Crohns & Colitis Association Inc.

PO Box 201

Mooroolbark 3138 Victoria

Telephone: (03) 9726 9008

Acknowledgement for reprint to the Crohns & Colitis Foundation of America

Further Patient Information Sheets & Updates at:- http://www.nevdgp.org.au/tbbase.htm