Black stools after hemorrhoid surgery are usually unrelated to hemorrhoid surgery; bleeding hemorrhoids are usually resolved as bright red stools. Black stool after hemorrhoid surgery may be due to other causes. The common causes of black stools are gastrointestinal bleeding or taking medications or foods that cause stools to turn black. 1. Gastrointestinal bleeding: mostly caused by bleeding in the upper gastrointestinal tract, such as gastroduodenal ulcer, portal hypertension, gastric space-occupying lesions, etc., the blood in the gastrointestinal tract to generate black iron sulfide, which makes the color of the stool black. 2. Foods and drugs that cause black stool color: some black foods, such as black rice, black sesame, black beans, etc.; all kinds of blood products, such as pig’s blood, duck’s blood, etc.; iron-containing foods or drugs, such as pig’s liver and other animal offal, iron; other drugs, such as bismuth, and so on. Taking food or drugs due to black stool generally stop taking 3 days after the stool color can return to normal. After hemorrhoid surgery, such as short-term black stool, you can observe the changes in the condition, consider the possibility of hemorrhoid surgery wound chronic bleeding, oozing blood in the intestinal tract retention time is too long caused by, such as a long-term situation of solving the black stool should be considered for other reasons. The above black stool situation, it is recommended to go to the hospital in time for further examination to clarify the cause of the disease, follow the doctor’s instructions, to avoid causing delays in the condition.