Hidden or obscure, such as occult blood in a sample of faeces.
Describing something that is not easily seen. Occult blood in the faeces is present in very small amounts and can be identi?ed only by a chemical test or under the microscope.
adj. not apparent to the naked eye; not easily determined or detected. For example occult blood is blood present in such small quantities that it can only be detected microscopically or by chemical testing. See faecal occult blood test.
The presence in the faeces of blood that cannot be seen by the naked eye, but can be detected by chemical tests. Such tests are widely used in screening for cancer of the colon (see colon, cancer of). Faecal occult blood may also be a sign of a gastrointestinal disorder such as oesophagitis, gastritis, or stomach cancer; cancer of the intestine (see intestine, cancer of); rectal cancer (see rectum, cancer of); diverticular disease; polyps in the colon; ulcerative colitis; or irritation of the stomach or intestine by drugs such as aspirin. (See also rectal bleeding.)... occult blood, faecal
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