What is the current thinking about Crohn's disease and Nutrition?

(from 'Medscape Primary Care)


When people have undergone multiple bowel resections and have 'short bowel syndrome,' osmotic diarrhoea secondary to a high carbohydrate diet and fat malabsorption may result. What is the optimal dietary management of these patients, and when is a total parenteral nutrition (TPN) indicated?

response from Charlene McClure Morris

Crohn's disease is considered an inflammaroty bowel disease, and can fistulate 'patch' areas of the gastrointestinal tract anywhere from the stomach and duodenum to the ileum and the rectum/anal region. (Harvey) Crohn's disease may also be called a leaky gut. However, this leaky gut syndrome may entail several disease processes, such as diabetes, lupus, and multiple sclerosis, that interfere with normal nutrient absorption and may not necessarily include the pain and progressive, episodic destruction known to exist with Crohn's disese.[1]

The initial management of Crohn's disease is medical. Aminosalicylates, such as sulfasalazine, are a first-line treatment, whereas prednisone class medications often follow. Continued, dynamic reassessment of the patient's tolerance and response to these regimens may require addition or substitute medications. If the third choice of immune modifiers, such as methotrexate, is ineffective, antibiotics, such as ciprofloxacin and metronidazole, may be needed. Surgery to remove affected areas is considered when medical treatment is ineffective.

Dietary modifications have been studied, but if there is no specific dietary restriction, foods may be eaten as tolerated. Even if a patient is lactose intolerant, a bifidus culture yogurt may be toloerated and beneficial in terms of ensuring an adequate supply of calcium, protien, and potassium. Laboratory studies should be used to determine anaemia and metabolic deficiencies. Basic testing should include a complete blood count, (CBC), folic acid, B12, calcium, BUN, albumin with total and a/g ratios, and carotene measurement. If diarrhoea is significant, fecal fat stool studies can determine the degree of malabsorption. Remember that measuring body weight is a good, inexpensive tool to monitor nutrition and should be done regularly in the medical office and by the patient.[2]

It is also important to consider a referral to a dietitian, who can review and reinforce nutrition basics with the patient. With ileum resections of less than 100 cm, osmotic diarrhoea, or inadequate bile salts from the liver to aid absorption of the meal, is often the cause of diarrhoea. The treatment of choice is cholestyramine,(Questran) in doses up to 4g. orally 3 times a day, 1 hour befor or after medications. (This dosing schedule is preferred so as not to interfere with crucial medications, such a digoxin.) Cholestyramine, used off-label, serves 2 purposes: the resin binds the hydroxylated bile acids, reducing aqueous concentration, and decreases the proportions of the bile acid pool available. [3]

A greater than 100 cm. resection of ileum is associated with true malabsorption syndrome. In this case, a therapeutic supplement of medium-chain triglyceride oil replaces longer-chained triglycerides that canot be absorbed. Doses range from 10-30 cc 3 times a day and are usually well tolerated, although expenive. Conversely, cholestyramine may actually aggravate diarrhoea in the patient with a larger ileum resection.[3]

Nutritional supplements for people with Crohn's disease should include a multiple vitamin with iodine, selenium, zinc, tocopherol, and magnesium, Iron, especially for women, and B6 for men are also important. Consider B12 injections,-- 1 cc each month.[4] Do not forget the propensity to developing osteoporosis with Crohn's disease patients! This occurs from calcium and vitamin D deficiencies, cachexia associated with malnutrition, and causes related to prednisone use. Screen and, if appropriate treat the osteoporosis.[5]

Total parental nutrition (TPN) is only necessary when these modalities have failed to provide quality nutrition and a sustained body weight with patient tolerance. Cases of extensive bowel resection, significan fistulae, or an extensive ileostomy may require TPN to maintain basic survival.

In summary, the indications for nutritional support in Crohn's disease are still largely based on clinical experience rather than randomized trials. In this approach, the presence and severity of malnutrition, the severity of the stress response, and the duration of inadequate feeding become the 3 variables used to define the need for parenteral and enteral nutrition rather than the disease diagnosis, per se. Such a scheme is based on the principle that the well-nourished individual can tolerate 5-7 days of inadequate feeding in the setting of moderate stress with minimal funtional consequence and that greater degrees of malnutrition or stress shorten this period.

Updated July 2003