Researchers from Taiwan assessed the specificity of the test in 1,654 men and 1,142 women who did not have symptoms of major GI disorders or bleeding.
Patients were interviewed and assessed with iFOBT, blood tests, colonoscopy and an upper GI tract endoscopy.
During the study, 14% of participants had a positive iFOBT result. Lesions in the lower GI tract were more frequent in those with positive test results.
The frequency of lesions in the upper GI tract was similar whether participants had positive or negative results.
Overall, iFOBT results were specific for 90% of colorectal cancers, adenomas and important lower GI lesions.
The researchers said their results supported the use of faecal occult blood testing as a specific diagnostic tool.