Short report: plasma somatostatin concentrations in the irritable bowel syndrome.

The description of a patient with the irritable bowel syndrome whose symptoms were completely relieved by the administration of somatostatin raised the possibility that a deficiency of somatostatin may be involved in the pathogenesis of the disorder. We have examined this possibility by studying 11 healthy controls (35 +/- 12 years; mean +/- S.D. 8 female) and 10 irritable bowel syndrome patients (39 +/- 14 years; 7 female) complaining of frequency of defaecation of 4 or more times a day. Plasma somatostatin concentrations were determined by specific radioimmunoassay, fasting and at 15, 30, 45, 60, 90, 120 and 180 min after a standard breakfast. Irritable bowel syndrome patients and controls had similar fasting (27.4 +/- 5.1 vs. 35.2 +/- 4.3 pg/ml; mean +/- S.E.M. and integrated increment of post-prandial (5105 +/- 858 vs. 3885 +/- 793 pg.min/L) plasma concentrations of somatostatin, as assessed by student's t-test. These observations do not support the idea that a state of somatostatin deficiency exists in the irritable bowel syndrome.