(75)SEHCAT TEST IN THE ASSESSMENT OF BILE -ACID MALABSORPTION - VALIDATION AND CLINICAL-SIGNIFICANCE

Objectives and methods. - The performances and the clinical significan ce of a simplified version of the (75)SeHCAT test which measures ileal absorption of bile salts were assessed in 23 healthy subjets and 106 patients. Corporeal retention of the marker was measured using an unco llimated gamma-camera. Results. - In healthy subjects, the (75)SeHCAT retention was lower in the group of 9 with an osmotic diarrhoea induce d by a PEG solution than in the group of 14 tested in normal condition s(22 +/- 4 % vs 44 +/- 4 %; P < 0.01). The reproducibility of the meas ure was good (r = 0.93 P < 0.001). The sensibility and specificity of the test for the diagnosis of ileal involvement were 79 % and 90 % res pectively. Bile acid malabsorption was evidenced in 38 % of patients w ith functional diarrhoea (59 % and 28 % in patients with and without p revious cholecystectomy respectively; P < 0.02) In patients with fonct ional diarrhoea, a correlation was evidenced between the orofaecal tra nsit time and the (75)SeHCAT retention (r = 0.66; P < 0.001) and chole styramine improved diarrhoea in 8 out of 11 patients with (75)SeHCAT m alabsorption and in 2 out of 5 patients with normal test. These result s show that the (75)SeHCAT test is accurate and that bile acid malabso rption, frequently evidenced in functional diarrhoea, is correlated wi th an acceleration of intestinal transit.