Long-term effects of elemental and exclusion diets for Crohn's disease.

Previous studies have confirmed the therapeutic value of elemental diets in promoting remission in active Crohn's disease, but their long-term benefit has not been established. Twenty-seven patients with established Crohn's disease who attained clinical remission after four weeks of enteral feeding were followed prospectively for up to 36 months. Twenty of these were willing to be tested for specific food intolerance using a pre-defined dietary elimination protocol; the others continued on a normal unrestricted diet. Eighteen patients (67%) have since relapsed; 89% of the relapse occurred within the first 6 months. Of the 15 patients with colonic involvement, 12 (80%) relapsed by 6 months. In contrast only 3 of 11 with isolated small bowel disease experienced early relapse. Of the 14 patients who completed the process of dietary testing, 5 could not identify any trigger foods; the remaining 9 were maintained on exclusion diets, 3 of whom relapsed early. Of the 11 taking a normal diet, 9 relapsed. Disease duration, previous intestinal resection or prior steroid therapy did not affect the relapse rate. Eight patients (31%) obtained a long-term remission, mean 23 months (range 12-36 months), without any medication. Long-lasting remissions can be obtained in about one-third of patients with Crohn's disease following treatment with a defined formula diet. Colonic involvement is associated with a high early relapse rate.