Nutrition in inflammatory bowel disease.
The diet of industrialized nations may contribute to the pathogenesis of both ulcerative colitis (UC) and Crohn disease (CD). Malnutrition is relatively unusual in UC, but in CD, which often affects the small intestine, it is frequent and may be severe. Nutrition support is therefore frequently indicated. First principles of artificial nutrition can be applied effectively using the gut whenever possible. Parenteral nutrition is generally required only in those with short bowel syndrome. An increasing literature (especially in pediatrics) favors the use of defined exclusive enteral nutrition (EN) in the primary treatment of active CD. Controlled trials are, however, lacking, and recommendations are accordingly not of the highest rank. It appears that in this context, simple polymeric regimens are usually sufficient, and there is currently insufficient evidence to make a strong recommendation for disease-specific feeds. In the maintenance of remission in CD, controlled data demonstrate that defined EN reduces the risk of relapse requiring steroid treatment. There are no data in support of primary nutrition therapy in UC either in management of the acute flare or in maintenance. In conclusion, nutrition therapy in adults with inflammatory bowel disease is probably both undervalued and underused, but the evidence base needs to be strengthened to confirm its efficacy, determine better those patients most likely to benefit, and optimize the regimens to be employed.