Home > Encyclopedia of Cancer > Fecal Occult Blood Test

Definition

The fecal occult blood test (FOBT) is performed as part of the routine physical examination during the examination of the rectum. It is used to detect microscopic blood in the stool and is a screening tool for colorectal cancer.

Purpose

FOBT uses chemical indicators on stool samples to detect the presence of blood not otherwise visible. (The word "occult" in the test's name means that the blood is hidden from view.) Blood originating from or passing through the gastrointestinal tract can signal many conditions requiring further diagnostic procedures and, possibly, medical intervention. These conditions may be benign or malignant and some of them include:

• colorectal and gastric...