In a previous study, chromogranin A (CgA) cell density in the colon of patients             with irritable bowel syndrome (IBS) was found to be reduced. It has been suggested             that intestinal CgA cell density may be used as a marker for the diagnosis of             IBS. The rectum harbours a larger number of large intestinal endocrine cells and             is more accessible for biopsies than the colon. The present study aimed at determining             the CgA cell density in the rectum of IBS patients. A total of 47 patients with             IBS that fulfilled the Rome Criteria III (39 females and 8 males; average age,             38 years) were included. A total of 28 patients had diarrhea (IBS-D) and 19 had             constipation (IBS-C) as the predominant symptom. A total of 27 subjects that underwent             colonoscopy with rectal biopsies were used as the controls. These subjects underwent             colonoscopy due to gastrointestinal bleeding (the source of which was identified             as haemorrhoids or angiodysplasia; 19 females and 8 males; average age, 49 years),             or health worries. The rectal biopsies were immunostained for CgA and quantified             by computer image analysis. The CgA density in the controls was 206.3±22.2 (mean             ± SEM), in all IBS patients 190.2±14.3, in IBS-D patients 188.8±14.7 and in IBS-C             patients 195.3±34.1. There was no statistically significant difference between             the controls, IBS, IBS-D or IBS-C patients (P=0.5, 0.5 and 0.7, respectively).             The present study showed that although the rectum comprises the same endocrine             cell types as the colon, attention must be paid when drawing conclusions regarding             the whole large intestine from studies carried out on the rectum. This particularly             applies when endocrine cells are investigated. As CgA cell density represents             the total endocrine cell content of the rectum, changes in specific endocrine             cells in IBS patients cannot be excluded.
Adolescent Adult