Cap-assisted gastroscope versus cap-assisted colonoscope for examination of difficult sigmoid colons in a nonsedated Asian population: a randomized study.

Background: Studies have estimated that cecal intubation failure occurs with conventional colonoscopy in about 10% of cases. Various methods have been adopted to improve the cecal intubation rate, including a transparent cap and special colonoscopes.

Objective: To assess the efficacy of using a cap-assisted gastroscope (E-cap) compared with a cap-assisted colonoscope (C-cap) for the complete examination of the colon in nonsedated patients with technically difficult sigmoid colons.

Design: Randomized, controlled study.

Setting: Tertiary-care referral center.

Patients: One hundred thirty-nine patients with technically difficult sigmoid colons were studied.

Intervention: Colonoscopy with either an E-cap (n = 69) or a C-cap (n = 70).

Main Outcome Measurements: Cecal intubation rate, cecal intubation time, patient-assessed pain score, and endoscopist-assessed pain score.

Results: The cecal intubation rate was significantly higher in the E-cap (65/69, 94.2%) than in the C-cap group (50/70, 71.4%; P < .0001). Patient-assessed pain (moderate to severe) was more frequently reported in the C-cap (14/70, 20.0%) than in the E-cap group (5/69, 7.2%; P = .029). Endoscopist-assessed pain (moderate to severe) was more frequently reported in the C-cap (13/70, 18.6%) than in the E-cap group (3/69, 7.2%; P = .009). For patients with a low body mass index (≤ 22 kg/m(2)), the cecal intubation rate was significantly higher in the E-cap (37/38, 97.4%) than in the C-cap group (15/29, 51.7%; P < .0001).

Limitations: Single-center experience, lack of a gastroscope control group without a cap.

Conclusion: The cap-assisted gastroscope is more tolerable and effective than cap-assisted colonoscope for the complete examination of the colon in patients with technically difficult sigmoid colons. (

Clinical Trial Registration Number: KCT0000744.).