Pediatric vs Adult Colonoscopes' Effectiveness in Obese Patients: The PACE Randomized Clinical Trial

Obesity is highly prevalent among US adults and is linked to a higher risk of colorectal neoplasia, making it essential to optimize colonoscopy for this population. However, comparative data guiding colonoscope selection in obese individuals remain limited.

A randomized equivalence clinical trial conducted at 2 Cleveland Clinic Florida locations included patients aged 18 years or older with a body mass index of ≥30 kg/m 2 , scheduled for screening or surveillance colonoscopy. The primary outcome was a composite of successful cecal intubation within 10 minutes without the need for scope exchange. Participants were randomly assigned in a 1:1 ratio to slim (pediatric) or adult colonoscopes.

A total of 245 participants entered the study protocol between January and September 2025. The primary endpoint was achieved in 94.3% of the slim colonoscope group and 92.6% of the adult colonoscope group, resulting in an unadjusted absolute risk difference of 1.7% (95% CI: -4.3% to 8.2%). This confirms equivalence within the predefined ±10% margin. After adjusting for sex, body mass index, bowel preparation quality, diverticulosis, and surgical history, the adjusted risk difference was 2.6% (95% CI: -4.3% to 8.6%). Secondary outcomes, including insertion time, withdrawal time, overall cecal intubation rate, terminal ileum intubation rate, adenoma detection rate, and use of ancillary maneuvers, were similar between the study groups.

Among expert endoscopists, slim and adult colonoscopes are equivalent in facilitating nondifficult colonoscopy in obese patients, with a trend toward improved performance using the slim colonoscope.