Oligo-antigenic diet in the treatment of chronic anal fissures. Evidence for a relationship between food hypersensitivity and anal fissures

OBJECTIVES: Patients with chronic constipation due to food hypersensitivity (FH) had an elevated anal sphincter resting pressure. No studies have investigated a possible role of FH in anal fissures (AFs). We aimed to evaluate (1) the effectiveness of diet in curing AFs and to evaluate (2) the clinical effects of a double-blind placebo-controlled (DBPC) challenge, using cow's milk protein or wheat. METHODS: One hundred and sixty-one patients with AFs were randomized to receive a "true-elimination diet" or a "sham-elimination diet" for 8 weeks; both groups also received topical nifedipine and lidocaine. Sixty patients who were cured with the "true-elimination diet" underwent DBPC challenge in which cow's milk and wheat were used. RESULTS: At the end of the study, 69% of the "true-diet group" and 45% of the "sham-diet group" showed complete healing of AFs (P