Noninvasive Measurement of Transit Time in Short Bowel Syndrome
Abstract
Background: Patients with short bowel syndrome (SBS) have limited absorption of nutrients, in part because of the rapidity with which chyme passes through the bowel. We sought to evaluate noninvasive measurements of intestinal transit time to aid in research questions where transit is measured repeatedly. Methods: Three methods were compared in 8 patients with SBS: the time for blue food color to appear in ostomy effluent or stool, lactulose breath hydrogen testing, and the first radiopaque ring from a capsule in timed stool samples. Results: Median blue dye fasted transit was 96.3 minutes, with breakfast was 117.3 minutes, and with lactulose was 72 minutes. By breath hydrogen testing, transit time was 52.5 minutes but detectible in only 5 of 13 tests. Transit time by radiopaque marker was 967 minutes, but no markers passed in 7 of 14 tests. Conclusions: Visualization of blue food color in ostomy effluent is a simple, inexpensive approach that can be applied to fasted subjects or after specific meals. Breath hydrogen testing should only be applied in the rare patient with SBS who has an intact ileocecal valve. Radiopaque markers are less useful, most likely because they become trapped due to anatomic changes.