Measurement of 75Se-SeHCAT Abdominal Retention in the Initial Diagnosis of Bile Acid Absorption (BAM)

Aim

To evaluate the usefulness of the ⁷⁵SeHCAT abdominal retention (AR) measurement in the early diagnosis of diarrhea syndrome (DS).

Methods

Thirty-seven patients with diarrhea syndrome within the first month of evolution were prospectively evaluated. The ⁷⁵Se-SeHCAT abdominal retention was measured 4 and 7 days post-administration of 0.01 mCi of ⁷⁵SeHCAT. The test was performed prior to treatment and at 3 months when the baseline study was positive. The test was considered positive if the RA was <25% at 4th and <10% on the 7th day. The patients were followed up at 3 months. Depending on the response, 3 groups were established: (a) complete response: normalization of stool frequency, (b) partial response, decrease of frequency and (c) no response.

Results

Group A: The AR of ⁷⁵Se-SEHCAT was normal in 21 patients. Six were diagnosed of colonic diverticulosis, 8 of irritable bowel syndrome, 1 of lymphocytic colitis, 1 of post-gastroenteritis syndrome, 1 of celiac disease and 1 of stenosis of the cardia. Four are still under study. Group B: The AR of ⁷⁵Se-SEHCAT decreased in 16 patients. All showed abnormal AR at day 7 and all but 1 at day 4. Following administration of cholestyramine resin, 8 (50%) presented partial response and 8 presented (50%) complete response. At 3 months, AR had increased at day 4 and 9 at day 7.

Conclusion

The measurement of ⁷⁵SEHCAT abdominal retention allows the early diagnosis of bile acid malabsorption in 43% of the patients with DS. Measurement at 7 days seems more accurate than that at 4 days.