General gastrointestinal dysmotility occurs in patients with irritable bowel syndrome (IBS). Ghrelin seems to play an important role in regulating gastrointestinal motility. The present study was undertaken, therefore, to establish the possible role of ghrelin in the pathophysiology of IBS. Thirty-seven patients with IBS (19 had IBS-constipation and 18 IBS-diarrhoea) were included in this study. Ten healthy volunteers served as controls. After overnight fast, blood samples were drawn from patients and controls, and a gastroduodenal endoscopy was performed. Biopsies were taken from oxyntic mucosa and duodenum. Ghrelin cell density was determined by computer image analysis after immunohistochemical staining of the tissues. Total and active ghrelin were detected in tissue extracts and plasma by commercially available RIA and ELISA Kits. The density of ghrelin-immunoreactive cells in the oxyntic mucosa was significantly lower in IBS-constipation and significantly higher in IBS-diarrhoea patients than healthy controls (P<0.0001 and <0.0001, respectively). There was no statistical difference in total or active ghrelin between IBS patients and controls, regarding tissue extracts or plasma. In order to compensate for the increase and decrease in the ghrelin cell density, the synthesis and release of ghrelin may be decreased and increased in IBS-diarrhoea and IBS-constipation patients, respectively. It has been speculated that this compensatory mechanism may be subjected from time to time to fatigue with the subsequent increased and decreased synthesis and release of ghrelin in IBS-diarrhoea and IBS-constipation with a subsequent intermittent diarrhoea or constipation seen in these patients, respectively.

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