Low-residue diet (LRD) in patient improves the quality of the colon cleanliness and thus the adenoma detection rate (ADR). This is a key criterion in colonoscopy screening for colorectal cancer (CRC). The benefit of an LRD lasting more than 24 hours before colonoscopy has not been demonstrated compared to a 24-hour LRD.

Few studies have evaluated the benefit of a prepackaged 24-hour LRD compared to simply receiving oral and written LRD instructions during a consultation.

The aim of the study is to evaluate the usefulness of a prepackaged LRD (Colobox®) compared to simple LRD instructions on colon cleanliness (Boston score) in patients examined by endoscopy.

Inclusion Criteria:

• Patient of one of the investigators for total colonoscopy (no prior colonic surgery);
• Patient aged 18 years or older;
• Patient classified as ASA 1, ASA 2, or ASA 3;
• Not participating in any other current clinical trial;
• Free, informed, and signed consent;
• Patient affiliated with or a beneficiary of a social security scheme, according to Article L.1124-1 of the French Public Health Code;

Exclusion Criteria:

• Patient taking major psychotropic medications;
• Patient with uncontrolled diabetes;
• Patient with coagulation abnormalities preventing polypectomy: PT <50%, Platelets <50,000/mm³, current effective anticoagulation therapy (clopidogrel, prasugrel, or ticagrelor);
• Patient referred for removal of a known polyp;
• Chronic inflammatory bowel disease;
• Known colonic stenosis;
• Diverticulitis of less than 6 weeks duration;
• Pregnant, parturient, or breastfeeding woman;
• Patient deprived of liberty by administrative or judicial order, or under guardianship or limited legal protection;
• Patient unable to understand the objectives and constraints of the study.