Fecal occult blood test paper shows one dark and one light means that the fecal occult blood test is weakly positive, leading to weakly positive fecal occult blood for a number of reasons, such as the consumption of pig’s blood and other physiological factors, as well as gastric ulcers, Crohn’s disease and other pathological factors. 1. Consumption of pig’s blood: If you have eaten animal blood or animal blood products, it may lead to a weakly positive fecal occult blood test, at this time to stop eating for a period of time and then review, usually can be turned into negative. 2. Gastric ulcer: the gastric mucous membrane barrier is destroyed under the attack of gastric acid and pepsin, forming a partial defect of the gastric wall, and a weakly positive fecal occult blood test will occur when the small blood vessels are damaged. 3. Crohn’s disease: due to the patient’s immune abnormality, genetic factors such as ileum, colon and other intestinal mucosa ulceration, erosion, inflammation, resulting in intestinal dysfunction, which leads to a weakly positive fecal occult blood test. It is recommended that patients follow the doctor’s instructions for further examination to clarify the specific causes of the disease and actively treat it.