Optical colonoscopy is the only examination allowing complete visualization of the colon with simultaneous polyp removal. In a minority of patients, a complete examination is unsuccessful. It is unknown whether single-balloon, overtube-assisted colonoscopy (SBC) is superior to simply repeating a standard colonoscopy (SC) on an alternate day.

To compare the success rates of SC and SBC in patients with previous incomplete examinations.

Randomized, controlled trial.

Tertiary care academic center.

Thirty subjects with previous incomplete colonoscopy.

Repeat colonoscopy either by SC or SBC. If cecal intubation was unsuccessful, subjects were crossed over to the alternate group.

Thirty subjects (73.3% female, mean age 59.2 years) with previous incomplete colonoscopy were randomized (SBC, 14 subjects; SC, 16 subjects). Cecal intubation was significantly more successful with SBC (92.9%) than with SC (50%) (P = .016). For all SC failures, cecal intubation was successful after crossover to the SBC group (100%). Cecal intubation time was similar in both groups. Proximal colon adenomas were detected in 38.1% of subjects. There were no procedure-related complications.

Singe endoscopist performing all procedures; inability to ensure all incomplete colonoscopies were included in the study.

For patients with a previous incomplete colonoscopy, balloon colonoscopy performed by using the single-balloon enteroscope with an overtube was superior to a repeat attempt with a standard colonoscope. For patients with a previous incomplete examination, consideration should be given to a repeat attempt with balloon colonoscopy if available. (Clinical trial registration number: STU00008540.)