Two days after cholecystectomy, the stool is a little black, may be caused by diet, or taking drugs caused by adverse reactions, but also should be alert to the upper gastrointestinal bleeding caused. 1. Dietary factors: after cholecystectomy, the digestive function of the stomach and intestines will be affected by the operation, and it is easy to suffer from indigestion and constipation in a short period of time after the operation, or eat food that affects the color of the stool, which will result in the black color of the stool. 2. Drugs: After cholecystectomy surgery, you need to take drugs for a long time, such as painkillers, anti-inflammatory drugs, cholestyramine, the adverse reactions of the drugs are more, and you are prone to black stool, indigestion, abdominal pain, diarrhea and other symptoms after taking the drugs. 3. Gastrointestinal bleeding: after cholecystectomy, if gastrointestinal bleeding occurs, it may cause black stool color, and in severe cases, it may cause blood in the stool. It is recommended to observe for a period of time if you have black stool for two days after cholecystectomy. If this happens for a long period of time, you should consult a doctor and analyze the cause of the disease through routine stool examination and then carry out regular treatment.