We have examined the occurrence and distribution of endocrine cells storing serotonin and the regulatory peptides somatostatin, glicentin, peptide YY in rectal mucosa on 16 patients with prolapse or intussusception of the rectum. There were no significant differences compared with normal rectal mucosa. Our results do not support the assumption that these endocrine cells of the rectum are involved in the pathophysiology of rectal prolapse.