Special issues in nutritional therapy of inflammatory bowel disease

Abstract

There are many issues and controversies concerning nutrition in inflammatory bowel disease (IBD). Most authorities now accept that total parenteral nutrition (TPN) is useful, both as primary and adjunct therapy in the management of patients with Crohn's disease, but only useful as adjunct therapy in patients with acute flare-ups of ulcerative colitis. In both, there is a role for TPN in preparing patients for imminent surgery. In comparison with TPN, defined formula (elemental diet) therapy has less complications, is easier to monitor, is less costly, and gives equivalent results. Several controlled trials have shown that elemental diet therapy is as useful as prednisone in inducing remission in patients with active Crohn's disease. Elemental diets have been compared with polymeric diets in patients with Crohn's disease, and have been shown to be effective; recently a semi-elemental diet has also been shown to be as effective as elemental diet, but with a conferred benefit of maintaining essential fatty acid levels. Elemental diets do not appear to be effective in closing fistulas. If the problems of palatability and, in some patients, nausea, vomiting, abdominal cramps and diarrhea persist, these can be overcome to some extent by flavour changes, chilling, gradual introduction and counselling or nasogastric tube feeding. Recently, fish oils have been used in patients with IBD. There is suggestive evidence that they are of benefit in patients with ulcerative colitis but not in Crohn's disease. There is a suggestion that fish oils have a steroid-sparing effect which, if confirmed, will be of great potential benefit to patients with ulcerative colitis.