Positive fecal occult blood initially indicates the presence of bleeding symptoms in the digestive tract. The following types of diseases cause bleeding symptoms in the digestive tract: 1, ulcerative diseases of the digestive tract, common types of disease are gastric ulcer, duodenal ulcer, colonic ulcer, etc., because the local digestive tissues ulcerative lesions, the lesions have smooth muscle contraction spasm and external material stimulation, there will be tissue fluid, blood exudation phenomenon, and will be mixed with excrement discharge, thus causing the phenomenon of positive fecal occult blood. 2.Occupying lesions in the digestive tract. The result is that the patient’s feces will be positive for fecal occult blood, such as anal fissure ulcer, septic anusitis, ruptured hemorrhoids, etc.