GASTROPARESIS AND SMALL-BOWEL DYSMOTILITY IN IRRITABLE-BOWEL-SYNDROME

Alterations in both gastric emptying (GE) and small bowel motility hav e been reported in irritable bowel syndrome (IBS); the relationship, h owever, between these different measures of upper gut motor function i n IBS has not been assessed. The aims of this study were therefore: (1 ) to compare the prevalence and characteristics of altered small bowel motility in IBS patients with and without delayed GE; and (2) to asse ss the interrelationships between fasting and postprandial small bowel motility in IBS, accounting for delayed GE. Forty-four IBS patients a nd 25 healthy controls underwent 24 hr ambulant recording of interdige stive and digestive small bowel motility. On a separate occasion the I BS patients had GE of both solids and liquids measured by a dual-isoto pe scintigraphic technique. Thirty-nine percent of IBS patients had de layed GE. Patients with normal GE had no interdigestive small bowel ab normalities. However, in patients with delayed GE fasting phase II bur st frequency was higher than in controls [median 0.21/hr (IQR 0.15-0.3 4) vs 0.06/hr (0-0,16), P = 0.004]. Postprandially, abnormal phase III -like activity was higher in diarrhea-predominant IBS patients (0-0.08 /hr vs 0/hr, P = 0.01), than in patients with normal GE or controls. F urthermore, IBS patients with delayed GE did not have the normal corre lation between fasting and postprandial motor parameters (percentage o ccurrence of clustered contractions, postprandial pattern duration vs preceding MMC cycle length). In conclusion, small bowel motor dysfunct ion occurs more frequently in IBS patients with concomitant gastropare sis than in patients with normal GE. These findings provide further ev idence that a neuropathic process may contribute to the pathogenesis o f IBS in a subgroup of IBS patients.