Reaction of rectal mucosa of celiac patients to direct contact with gluten.

It is assumed that the colonic mucosa of celiac patients is not sensitive to gluten. This assumption has been supported by the absence of clinical manifestations of colonic involvement in patients with active celiac disease which, by itself, does not confirm insensitivity to gluten. Eight children, aged from 11 to 25 months, with an initial diagnosis of celiac disease were studied: in five children a definite diagnosis has already been confirmed. Rectal gluten challenge was done by means of retention enemas. A volume of 100 ml of a 10% gluten suspension in water was introduced into the rectum three times per day for 8 days; each enema was retained at least 1 h. Rectosigmoidoscopies and rectal biopsies were done before and at the end of the challenge period. The endoscopic appearance of rectal mucosa was normal in all the children either before or after gluten challenge. The means of total mucosal thickness, intraepithelial lymphocyte counts, mitotic crypt cell activity, and cellular infiltration of lamina propria increased after challenge; the mean of goblet cell/epithelial cell ratio in the surface epithelium decreased. The differences between each pair of means (before and after challenge), however, were not significant except for total mucosal thickness (p less than 0.05), the meaning of which is unclear. This study did not definitely demonstrate that the rectal mucosa of celiacs is insensitive to gluten. For practical clinical purposes, however, it behaves as such. This makes the rectal mucosa a useless tool for the final diagnosis of celiac disease.