Authors: Miwa J, Echizen H, Matsueda K, Umeda N.

Institution: Division of Gastroenterology, International Medical Center of Japan, Tokyo, Japan. jun.miwa@po.toshiba.co.jp

Background: Serotonin (5-HT) may play an important role in the regulation of colonic motility in humans. However, it is not known whether alterations in the colonic 5-HT system are involved in the pathophysiology of irritable bowel syndrome (IBS).

Results: In all study groups, the mean mucosal 5-HT concentrations obtained from the rectum were significantly (p < 0.05) higher than those obtained from more cephalic regions of the colon. In addition, the overall mean mucosal 5-HT concentrations obtained from patients with constipation-predominant IBS were significantly (p < 0.05) higher than those obtained from the control subjects and patients with diarrhea-predominant IBS. No significant differences were observed in 5-hydroxyindoleacetic acid concentrations among the three groups.

Conclusions: The mucosal 5-HT concentrations in the colon showed an ascending cephalocaudal gradient in all study groups. Although the mucosal 5-HT concentrations were elevated in patients with constipation-predominant IBS as compared with those with diarrhea-predominant IBS and the control subjects, further studies are necessary to determine whether the elevated mucosal 5-HT is a cause or a result of abnormal colonic motility. Copyright 2001 S. Karger AG, Basel

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11351146&query_hl=16&itool=pubmed_docsum

• Irritable Bowel Syndrome: Update on Pathogenesis and Management
• Patients With Constipation-Predominant Irritable Bowel Syndrome (IBS) May Have Elevated Serotonin Concentrations in Colonic Mucosa as Compared With Diarrhea-Predominant Patients and Subjects with Normal Bowel Habits
• Abnormalities of 5-Hydroxytryptamine Metabolism in Irritable Bowel Syndrome