What happens if they can find the cause for a positive fecal occult blood test?
When the work up to evaluate occult fecal blood is completed (see colon cancer screening article below), about 5% of patients with gastrointestinal bleeding will not have a source for their bleeding found. In this case some additional studies may be needed and sometimes “oscopy” studies may need to be repeated with different or more experienced gastorenteroscopists. A radioactive technetium-99m scan may be performed which can detect as small a blood loss as 0.1 ml per minute. It is useful only to confirm that there is GI bleeding and where in the GI tract,in general, the bleeding is occurring. It still does not diagnose the cause. Enteroscopy is another study that may be used to look at the small intestine which cannot be seen with gastroscopy (looking in the stomach) and colonoscopy (looking up the colon). Sometimes even after all these studies, a source of the bleeding may be found. When that happens the best that can be done is just to have close follow up and occasionally repeat an
