Low Densities of Serotonin and Peptide YY Cells in the Colon of Patients with Irritable Bowel Syndrome

Background The gut hormones are important in regulating gastrointestinal motility. Disturbances in gastrointestinal motility have been reported in patients with irritable bowel syndrome (IBS). Reduced endocrine cell density, as revealed by chromogranin A, has been reported in the colon of IBS patients. Aims To investigate a possible abnormality in the colonic endocrine cells of IBS patients. Methods A total of 41 patients with IBS according to Rome Criteria III and 20 controls were included in the study. Biopsies from the right and left colon were obtained from both patients and controls during colonoscopy. The biopsies were immunostained for serotonin, peptide YY (PYY), pancreatic polypeptide (PP), entroglucagon, and somatostatin cells. Cell densities were quantified by computerized image analysis. Results Serotonin and PYY cell densities were reduced in the colon of IBS patients. PP, entroglucagon, and somatostatin- immunoreactive cells were too few to enable reliable quantification