Blood in the urine after gastroenteroscopy is an abnormal phenomenon, and the possibility of pathological factors should be considered, such as urethral tumors and urinary tract infections. Gastroenteroscopy is an invasive examination, which can lead to gastrointestinal discomfort, pain and other symptoms; if the operation is not appropriate, it can lead to gastrointestinal bleeding, perforation, and then pus and blood stools, black stools, abdominal pain and other symptoms, but it usually does not lead to blood in the urine. The symptoms of blood in the urine, you should consider the possibility of urological diseases, such as urethral stones, urethral tumors, urinary tract infections, etc., may trigger this symptom; in addition, leukemia, hemophilia, dermatomyositis, acute hypertension and other diseases, can also trigger hematuria. The cause of hematuria is relatively complex; it is recommended to consult a doctor as soon as possible for examination and treatment under the doctor’s guidance.