Colonic lymphoid aggregates in slow transit constipation.

Information available on colonic lymphoid aggregates, apart from data of patients with inflammatory conditions, is scarce in other pathologic conditions. We investigated colonic lymphoid aggregates in patients with severe slow transit constipation, unresponsive to conventional therapeutic measures, and undergoing surgery for relief of their symptoms. Tissues from 27 patients with intractable slow transit constipation were obtained and compared with 10 controls. The number, diameter, lymphocyte distribution, and proliferative index were calculated and compared in both groups. Constipated patients displayed a significantly increased number of colonic lymphoid aggregates compared with controls. No differences were found concerning the other variables. The increase of colonic lymphoid aggregates found in severely constipated patients may represent a protective mucosal mechanism toward the chronic fecal stasis.