Fewer side effects but poorly tolerated and no more effective than corticosteroids

Oral corticosteroids (usually prednisolone) have long been the standard treatment for active Crohn's disease, being used within 10 years of diagnosis in 55% of patients. Their efficacy has been established in two multicentre, placebo controlled trials.1 2 After four months, remission was shown in 60-83% of patients compared with 30-38% of those receiving placebo. However, there is currently much concern over side effects. In the short term these trials showed that corticosteroid treatment significantly increased the prevalence of cutaneous problems (moon face, acne, bruising, and striae), hypertension, and infections. In the long term there is concern over osteoporosis. Although the exact incidence is not known, substantial bone loss has been shown in patients taking at least 7.5 mg prednisolone daily, and about a quarter of patients receiving long term treatment will experience a fracture.3

For these reasons, other treatments have been sought. In the past 12 years dietary treatment has been investigated in several centres with diets differing in …