A comparative study of three fecal occult blood tests in upper gastrointestinal bleeding.

The purpose of this study was to evaluate the performance characteristics of three fecal occult blood tests (FOBTs): the chemical o-toluidine test, the immunochemical OC-Hemodia test, and the immunochromatographic Quick Chaser Occult Blood (QCOB) test, which detect human hemoglobin and transferrin simultaneously in cases of upper gastrointestinal (GI) bleeding. Included were 48 FOBT specimens in 48 consecutive admission cases of upper GI bleeding (endoscopy confirmed). We excluded those fecal specimens with an obvious tarry and bloody appearance. The QCOB test revealed the highest positive rates of 33/48 (68.8%), and significantly higher positive rates than that of the OC-Hemodia test and o-toluidine test (p < 0.025 and < 0.01, respectively). In the patient group with upper GI bleeding due to gastric and duodenal ulcers, the QCOB test had higher positive rates (68.6%) than did the o-toluidine test (34.3%) (p < 0.01). There was no fecal specimen that was positive for the o-toluidine test or OC-Hemodia test and was negative for the QCOB test. Our results reveal that the QCOB test has significantly higher positive rates of fecal occult blood than either the OC-Hemodia test or o-toluidine test. The QCOB test is better than the other two tests for detecting occult blood in patients with upper GI bleeding.