A Prospective Study of the Effect of Modified Colonoscopy Bowel Preparation Program on Intestinal Cleaning, Examination and Disease in Patients With Inflammatory Bowel Disease

Inclusion Criteria: * Diagnosis: inflammatory bowel disease (IBD) patients, including ulcerative colitis (UC) and Crohn's disease (CD), have colonic involvement. * Patients and/or family members can understand the study protocol and are willing to participate in the study and provide informed consent in writing. Exclusion Criteria: * The diagnosis is not definite. * Toxic megacolon, gastrointestinal perforation or other acute abdominal diseases; Patients with gastrointestinal bleeding with unstable vital signs. * Patients after colon surgery. * Serious underlying diseases, organ failure, or inability to cooperate with colonoscopy for other reasons. * Patients can not cooperate with the use of polyethylene glycol or glycerin enema. * Patients or family members cannot understand the conditions and objectives of this study.