Stomach pain one week after doing colonoscopy may be caused by intestinal injury, intestinal perforation, acute gastroenteritis and other reasons. 1. Intestinal injury: the intestinal mucosa may be damaged after colonoscopy, which will cause stomach pain. 2. Intestinal perforation: There is a lot of gas in the intestines as a result of colonoscopy, which can be gradually relieved in 1~3 days, and stomach pain in a week may be caused by intestinal perforation. 3. Acute gastroenteritis: after doing colonoscopy do not pay attention to dietary hygiene, eating bacterial infected food is easy to trigger acute gastrointestinal inflammation, resulting in stomach pain, accompanied by diarrhea, intestinal chirping and other symptoms. A week after the colonoscopy stomach pain involves more reasons, it is recommended to consult a doctor in a timely manner to identify the cause and then give treatment, so as not to delay the condition.