Constipation can do colonoscopy. Colonoscopy is a commonly used clinical method of lower gastrointestinal endoscopy, colonoscopy is more commonly used, commonly used to observe the anus to the ileocecal valve within the scope of colorectal lesions, applicable to blood in stool and change in stool characteristics to investigate the cause of the change in stool, the confirmation of the diagnosis of colorectal lesions, inflammatory bowel disease and colorectal cancer diagnosis and follow up, enteroscopic hemostasis and polypectomy, and so on. In the absence of severe anorectal stenosis, acute severe colitis, acute diffuse peritonitis, perforation of abdominal organs, severe cardiorespiratory failure, mental disorder and coma and other contraindications to colonoscopy, and not pregnant women, colonoscopy is feasible. Patients with constipation can also be cleansed after oral laxatives or enemas and other intestinal cleansing methods for this operation. Those who need to undergo colonoscopy should go to a regular medical institution in time and actively cooperate with the relevant diagnosis and treatment.