Orlistat is mainly used in clinical treatment of obese or overweight patients. Black oily stool after taking it is one of the adverse reactions of the drug, but it may also be tarry black stool caused by upper gastrointestinal bleeding. It is recommended to seek medical advice to clarify the cause of the disease and deal with it according to the cause. Common conditions and treatment 1, drug side effects: orlistat side effects are more common oily spotted stool, gastrointestinal exhaust, fecal incontinence, etc. These side effects are mainly related to orlistat to prevent the intake of fat absorption. Most people can improve after a period of medication, such as the emergence of severe or persistent abdominal pain, may be a signal of serious side effects, the need for timely consultation under the guidance of doctors to see whether to discontinue the drug; 2, upper gastrointestinal bleeding: you can go to the hospital to do routine stool examination and occult blood test, screening for gastrointestinal bleeding. If it is abnormal stool caused by gastrointestinal bleeding, you must seek medical treatment urgently to prevent bleeding from increasing causing shock. If it is non-esophagogastric fundic vein bleeding, you need to apply acid-suppressing drugs, such as omeprazole, to stop bleeding under endoscopy, and if it is esophagogastric-fundic vein bleeding, you need to apply growth inhibition, octreotide, and also need to apply balloon compression, endoscopic treatment, etc. to stop bleeding immediately. Precautions 1. You should consult your physician before using orlistat for the first time, and you should go to the hospital for regular check-ups during taking the drug. In particular, patients with hypertension, diabetes, kidney stones, pancreatitis, should be combined with other drugs under the guidance of a physician; 2, the use of the drug needs to be combined with exercise, control diet to achieve the slimming effect, after stopping the drug also need to continue to control the diet and exercise.