Low incidence of enterocolitis and colonic mucosal inflammation in Norwegian patients with Hirschsprung's disease

Hirschsprung's disease (HD) may be associated with inflammation in the colon. Further, the etiology of Hirschsprung-associated enterocolitis (HEC) is unclear. To learn more about these features, we examined our cohort of HD patients during a period of 6 years for inflammation in their colonic mucosa as well as for signs of HEC. Rectal suction biopsies and operative full thickness aganglionic and ganglionic colonic specimens from 36 patients were examined. Signs of inflammation were recorded in hematoxylin/eosin/saffron (HES)-stained sections and with fluorescence conjugated polyclonal antibodies to IgA and IgG applied on serial sections. The suction biopsies were also evaluated for the presence of mucus inspissation and crypt dilatation. Clinical signs of HEC were recorded from medical files of the same 36 patients. HES-staining revealed that seven patients had inflammation in the suction biopsies; these patients were significantly older than the patients without inflammation. Slight mucus inspissation was identified in suction biopsies of five out of 33 patients, but crypt abscesses or ulcerations were not found in any specimens. Virtually all very young patients (< 3 months) had slight crypt dilatation. We identified inflammation in resected colonic segments from 17 out of 36 patients. Thirteen of these 17 had a diverting colostomy, and only one out of 14 patients with colostomy had no inflammation. Inflammatory changes were similar in ganglionic and aganglionic bowel. By immunofluorescence (IF) staining, inflammation was found in resected colonic segments from five patients. Four of these had a colostomy. HEC was diagnosed in three patients, and inflammation detected in resected specimens from only one of these three. We have not been able to identify particular characteristics in the colonic or rectal mucosa that are linked to development of HEC. Inflammation in the resected specimen was mainly found in patients with a diverting colostomy, and then in both ganglionic and aganglionic colon.