Food intolerance and chronic constipation:: manometry and histology study

Background Chronic constipation in children can be caused by cows' milk intolerance (CMI), but its pathogenesis is unknown. Aims To evaluate the histology and manometry pattern in patients with food intolerance-related constipation. Patients and methods Thirty-six consecutive children with chronic constipation were enrolled. All underwent an elimination diet and successive double-blind food challenge. All underwent rectal biopsy and anorectal manometry. Results A total of 14 patients were found to be suffering from CMI and three from multiple food intolerance. They had a normal stool frequency on elimination diet, whereas constipation recurred on food challenge. The patients with food intolerance showed a significantly higher frequency of erosions of the mucosa, and the number of intra-epithelial lymphocytes and eosinophils. The rectal mucous gel layer showed that the food-intolerant patients had a significantly lower thickness of mucus than the other subjects studied. Manometry showed a higher anal sphincter resting pressure and a lower critical volume in food intolerance patients than in the others suffering from constipation unrelated to food intolerance. Both histology and manometry abnormalities disappeared on the elimination diet. Conclusions Food intolerance-related constipation is characterized by proctitis. Increased anal resting pressure and a reduced mucous gel layer can be considered to be contributory factors in the pathogenesis of constipation.