Original article 1 Food intolerance and chronic constipation: manometry and histology study Giuseppe Iacono a , Sebastiano Bonventre b , Calogero Scalici a , Emiliano Maresi c , Lidia Di Prima d , Maurizio Soresi d , Giuseppe Di Gesu ` b , Davide Noto d and Antonio Carroccio d Background Chronic constipation in children can be caused by cows’ milk intolerance (CMI), but its pathogen- esis 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 chal- lenge. All underwent rectal biopsy and anorectal mano- metry. 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 mucous 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 mano- metry 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 constipatio- n. Eur J Gastroenterol Hepatol 17:000–000  c 2005 Lippincott Williams & Wilkins. European Journal of Gastroenterology & Hepatology 2005, 17:000–000 Keywords: anorectal manometry, chronic constipation, eosinophil cell, food intolerance, rectal histology a Department of Pediatric Gastroenterology, ‘Di Cristina’ Hospital, Palermo, Italy, Departments of b Surgery, c Pathology and d Internal Medicine, University Hospital of Palermo, Palermo, Italy. Correspondence to Antonio Carroccio, MD, Medicina Interna, Policlinico di Palermo, via del Vespro 141, 90127 Palermo, Italy. Fax + 39 091 6552936; e-mail: acarroccio@hotmail.com This study was supported by a grant from the MIUR and MiPAF: project ‘Alimentazione e celiachia (ALICE)’ DD 86 dated 30 January 2002. Received ’’’ Accepted ’’’ Introduction Chronic constipation is a very common problem in children [1,2], but despite its high prevalence its cause remains unknown in the majority of cases. Our previous works indicated a clear relationship between cows’ milk intolerance (CMI) and chronic constipation in some of the patients [3,4], and it is now accepted that these children can be cured with a cows’ milk-free diet. However, the pathogenesis of the CMI-related constipa- tion is unknown. We have recently demonstrated the existence of an inflammatory condition associated with a reduction of the mucous layer on the rectal mucosa, and hypothesized that this second factor could contribute to the pathogenesis of the constipation [5]. However, the aspect of the anorectal motility in these patients has not previously been investigated. In the present study we considered a new series of consecutive patients suffering from chronic constipation and unresponsive to previous standard treatment to evaluate the histology and manometry characteristics of the cases of constipation caused by CMI. Patients and methods The study included all the consecutive infants and children with chronic constipation unresponsive to previous treatments examined at the outpatients clinic of the Pediatric Gastroenterology Division of the ‘Di Cristina’ Hospital, Palermo, Italy, between January and December 2000. Chronic constipation was defined as less than three bowel movement per week with painful elimination of hard stools. Inclusion criteria were: (i) a history of chronic constipa- tion lasting at least 3 months; (ii) a lack of response to a previous increase in dietary fibre intake or to laxative treatment (milk of magnesia 1–2 ml per kilogram of body weight); (iii) a regular dietary intake of cow’s milk and CE: xxx ED: Susan Op: mamatha MEG: lww_meg_200066 0954-691X  c 2005 Lippincott Williams & Wilkins