Weakly positive fecal occult blood test is not very common. The cause of weakly positive fecal occult blood test may be influenced by physiological factors such as food and drugs, or it may be caused by a small amount of gastrointestinal bleeding due to digestive or systemic diseases, such as gastroduodenal ulcers, inflammatory bowel disease, tumors and other diseases.
1. The influence of food and drugs: often due to the intake of iron-containing drugs, blood products (pig’s blood, sheep’s blood, duck’s blood) and so on, resulting in a weakly positive fecal occult blood test. If the fecal occult blood test is immunoassay, the influence of food and drug factors can be excluded.
2. Gastroduodenal ulcer: some lesions occurring in the mucosal layer or submucosal layer of the stomach and duodenum can lead to localized mucosal defects, which may cause bleeding, pain or even perforation in severe cases. When there is a small amount of bleeding from gastrointestinal mucosal lesions, a weakly positive fecal occult blood test may occur.
3. Inflammatory bowel disease: it is a kind of non-specific inflammatory disease that occurs in the colon, and the patients can show symptoms such as abdominal pain, diarrhea, mucus, pus and blood stools, and acute and severe symptoms. When there is a small amount of bleeding from intestinal mucosal lesion, fecal occult blood test is weakly positive.
4. Colon cancer: it is a malignant tumor occurring in the mucosal epithelium of colon. The colon includes ascending colon, transverse colon, descending colon, sigmoid colon, etc. And malignant tumors occurring in these parts are weakly positive in fecal occult blood test when there is mucosal lesion.
Fecal occult blood test weak positive may also have other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, give targeted treatment or standardized treatment.