Single-Balloon-Assisted vs Cap-Assisted Colonoscopy Superior for Difficult Intubations

Single-balloon-assisted colonoscopy could be considered a reliable rescue method after cecal intubation failure.

Single-balloon-assisted colonoscopy (SBC) demonstrated superior efficacy and similar safety compared with cap-assisted colonoscopy (CAC) among patients with previous cecal intubation failure, according to study findings published in the Journal of Gastroenterology & Hepatology.

Researchers conducted a randomized study in 2 tertiary hospitals to compare the SBC and CAC methods of cecal intubation among 44 patients with previously incomplete conventional colonoscopies. All colonoscopy procedures were performed by experienced gastroenterologists.

Of 379 patients identified with cecal intubation failure, 335 patients were excluded due to mechanical obstruction, poor bowel preparation, history of colectomy, successful repeat colonoscopy or death before recruitment, refusal to repeat colonoscopy, and defaulted follow-ups or identification of rectal or sigmoid tumors during initial conventional colonoscopy. For the analysis, researchers randomly assigned the remaining 44 patients 1:1 either to the SBC group or to the CAC group.

Gastroenterologists achieved successful cecal intubation in all patients (100%) in the SBC, whereas only 16 of 22 patients (72.7%) in the CAC group achieved successful cecal intubation. SBC demonstrated significant superiority to CAC in overcoming previously unsuccessful conventional cecal intubation (P =.02). Rates of intubation success did not differ between the 3 endoscopists. Intubation and withdrawal times also did not significantly differ.

[A] reliable rescue method after cecal intubation failure is important.

During the procedures, additional maneuvers, including manual abdominal pressure and change of patient posture, were needed in 36.4% of patients in the SBC group compared with 56.3% in the CAC group; however, there were no significant differences.

The 6 patients who failed the CAC method subsequently underwent the SBC procedure during the same session and achieved successful cecal intubation.

No procedure-related adverse complications or events were reported in either group.

“[E]ven for experienced endoscopists, cecal intubation failure by conventional colonoscopy may still be inevitable,” the study authors wrote. “Therefore, a reliable rescue method after cecal intubation failure is important. In our study, we demonstrated excellent efficacy and safety of utilizing SBC in overcoming this challenge with superiority over CAC.”

Study limitations include the lack of local endoscopy units (only 2) and endoscopists (only 3) affecting confounding factors, such as skill level of endoscopists and generalizability of results. Additionally, the use of a subjective outcome measure reported by unblinded assistant nurses may introduce personal bias into the study.


Cheng TF, Cheng KS. A randomized prospective study comparing single-balloon-assisted colonoscopy and cap-assisted colonoscopy in patients with previous incomplete conventional colonoscopy. J Gastroenterol Hepatol. Published online November 18, 2022. doi:10.1111/jgh.16062