Context: 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 (AF).~Objective: We aim to evaluate 1) the effectiveness of a diet in curing AF; 2) the clinical effects of a double-blind placebo controlled (DBPC) challenge with cow's milk protein or wheat.~Design: The study will have two different parts: the first to verify the effectiveness of the oligo-antigenic diet in chronic AF treatment; the second to search for a possible cause-effect relationship between the diet and the onset of the AF.~Setting: We will enrol consecutive adult patients with chronic AF who will refer to a Surgical Department of the University of Palermo for a 3-years period. Inclusion criteria are: evidence of CAF evaluated by an experienced rectal surgeon; patient age >16 years. Exclusion criteria are: a diagnosis of inflammatory bowel disease, ongoing steroid treatment performed for any reason, an exclusion diet followed for any reason, and pregnancy. At the time of the first evaluation, routine laboratory tests, immunology tests, rectal biopsies and anal-rectal manometry will be performed.~Patients: patients, finally included in the study, will be randomized to one of the treatment groups.~Interventions: Enrolled patients will be randomized to receive a true elimination diet or a sham elimination diet; both groups will also receive topical nifedipine and lidocaine.~Main Outcome Measures: The patients will be evaluated every two weeks for CAF persistence or healing; anal pain will be scored on a visual analogue scale ranging from 0 (absence of pain) to 10 (intolerable pain). Anal-rectal manometry will be repeated at the end of the study period, in all patients who will be treated.
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 (AF). We aim to evaluate the effectiveness of a diet in curing AF and the clinical effects of a double-blind placebo controlled (DBPC) challenge with cow's milk protein or wheat.