Blood in the urine after colonoscopy is not considered to be related to the performance of colonoscopy, and most of the blood in the urine comes from urologic diseases such as urinary stones, inflammation, and so on. Generally there is no special reaction and discomfort after colonoscopy, some patients may experience abdominal discomfort, often manifested as distension, or even colic. Very few patients may experience complications such as bowel perforation during the examination, but blood in the urine does not usually occur. Blood in the urine is blood mixed with urine, giving the urine a washed-out appearance or containing blood clots. The vast majority of blood in urine comes from diseases of the urinary system, such as urinary stones, inflammation or tumors, etc.; a small portion comes from organs adjacent to the urinary system or systemic diseases. Therefore, the cause of blood in urine is relatively complex, it is recommended that the patient consult a doctor in a timely manner, by the doctor to clarify the cause, and then give targeted treatment.