Individualized Non-pharmacological Intervention for Bowel Preparation

A total of 339 patients are enrolled and randomly assigned in a 1:1:1 ratio to the information-framing + individualized bowel preparation (BP) group, the individualized BP group, and the control group. All patients receive oral instructions on bowel preparation. On this basis, the control group receives a standard BP regimen and written educational materials; the individualized BP group is assessed using a risk prediction model for inadequate bowel preparation, with the results disclosed to the patients. Those with a risk score ≥3.25 receive an enhanced BP regimen, while those with a risk score <3.25 receive the standard BP regimen, and all patients in this group receive illustrated educational materials. In the information-framing + individualized BP group, educational materials are further tailored according to the information framework theory. Specifically, patients with a risk score ≥3.25 receive loss-framed materials emphasizing the harms of non-adherence, whereas those with a score <3.25 receive gain-framed materials highlighting the benefits of adherence. On the day of the colonoscopy, patients' willingness to undergo a repeat colonoscopy and the occurrence of adverse events are recorded in the waiting area. Patients also complete the Bowel Preparation Adherence Behavior Assessment Scale and the Treatment Self-Regulation Questionnaire. Bowel preparation quality is evaluated by endoscopists blinded to group allocation using the Boston Bowel Preparation Scale (BBPS), and polyp/adenoma detection rates are also recorded.

Inclusion criteria

• age ≥ 18 years;
• outpatient scheduled for colonoscopy using oral laxatives for bowel preparation;
• able to understand the study and provide written informed consent.

Exclusion criteria

• undergoing emergency colonoscopy;
• suspected intestinal obstruction, stricture, or perforation;
• severe cardiac, cerebral, hepatic, or renal disease;
• severe psychiatric disorder;
• impaired consciousness or communication difficulties;
• pregnancy or lactation;
• previous enrollment in this study.