This multi-center, prospective, randomized controlled trial evaluates whether disease subtype-based active video education improves bowel preparation quality in patients with inflammatory bowel disease (IBD) undergoing colonoscopy. A total of 600 IBD patients from 13 centers will be randomized 1:1 to standard education plus subtype-specific video education (intervention group) or standard education alone (control group). The primary outcome is the Boston Bowel Preparation Scale (BBPS) score.

Inflammatory bowel disease (IBD) patients often have suboptimal bowel preparation before colonoscopy due to chronic inflammation, strictures, and poor adherence to preparation protocols. Conventional written and verbal education has shown limited effectiveness in this population. This multi-center trial will develop and test an active video education intervention tailored to IBD subtypes (ulcerative colitis or Crohn's disease), delivered via WeChat before colonoscopy. A total of 600 patients from 13 participating hospitals across China will be randomized 1:1 to either the intervention group or the control group. Randomization will be stratified by center using a computer-generated sequence with allocation concealment (sealed, opaque envelopes). The primary endpoint is bowel preparation quality measured by the total BBPS score. Secondary outcomes include adequate/excellent preparation rates, cecal intubation rate and time, patient compliance, knowledge scores, adverse events, anxiety levels, and satisfaction. Outcome assessors will be blinded to group assignment to reduce bias. Statistical analyses will account for center effects (e.g., using mixed-effects models or including center as a covariate) and will be performed using appropriate methods based on data distribution.

Inclusion Criteria:

1. Age between 18 and 75 years, inclusive.
2. Confirmed diagnosis of Ulcerative Colitis (UC) or Crohn's disease (CD) according to standard clinical guidelines.
3. Scheduled for elective colonoscopy for IBD monitoring or disease activity assessment.
4. Able to understand written and verbal instructions and to use a smartphone to view video education materials.
5. Voluntary participation with written informed consent.

Exclusion Criteria:

1. Absolute contraindications to colonoscopy, including acute gastrointestinal perforation, fulminant colitis, toxic megacolon, or hemodynamic instability.
2. History of total or subtotal colectomy.
3. Acute or chronic intestinal obstruction.
4. Severe cardiac, pulmonary, hepatic, or renal insufficiency (eGFR <30 mL/min/1.73m², NYHA class III/IV).
5. Severe psychiatric or cognitive impairment that prevents understanding of the study requirements.
6. Inability or unwillingness to provide written informed consent.
7. Pregnant or breastfeeding women.

The individual participant data (IPD) for this study will not be made available to other researchers, due to concerns related to participant privacy, data confidentiality, and institutional data sharing policies.

Outcome assessors (endoscopists evaluating bowel preparation quality and research staff collecting data) will be blinded to participants' group assignment to minimize assessment bias.