Single-balloon colonoscopy versus repeat standard colonoscopy for previous incomplete colonoscopy: a randomized, controlled trial

Background: 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.

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

Design: Randomized, controlled trial.

Setting: Tertiary care academic center.

Patients: Thirty subjects with previous incomplete colonoscopy.

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

Results: 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.

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

Conclusions: 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.).