Authors: Tornblom H, Lindberg G, Nyberg B, Veress B.

Institution: Karolinska Institutet Department of Medicine, Huddinge University Hospital, Stockholm, Sweden. hans.tornblom@gastro.hs.sll.se

Background and Aims: Irritable bowel syndrome (IBS) is regarded as a functional bowel disorder. Few studies have looked for histopathologic changes in the gut and only then in biopsy specimens from intestinal mucosa. Because bowel function is governed mainly by nerve plexuses in the bowel wall, we have investigated full-thickness bowel biopsy specimens in patients with severe IBS.

Results: Ten patients (2 males, 8 females) were studied. In 9 patients, we found low-grade infiltration of lymphocytes in the myenteric plexus. Lymphocytes had peri- and intraganglionic location. The mean number of lymphocytes per ganglion ranged from 1.9 to 7.1 per patient, with an overall mean of 3.4.

No intraganglionic lymphocytes were found in the control group and only a few periganglionic lymphocytes (mean, 0.2). Four patients had concomitant intraepithelial lymphocytosis. Neuron degeneration was evident in 6 of 9 patients with and 1 patient without ganglionic lymphocyte infiltration.

Conclusions: Our findings indicate that inflammation and neuronal degeneration in the myenteric plexus are involved in the pathogenesis of IBS.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12454854&dopt=Abstract

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