Compared to two-operator single-balloon enteroscopy, single-operator procedure not only offer better maneuverability but may also prevent prolonged examination times and potential complications caused by poor coordination between operators. Additionally, it can optimize staffing in the endoscopy suite. However, there are no studies comparing the effects of single-operator and two-operator techniques on single-balloon enteroscopy.

Balloon-assisted enteroscopy (BAE) has been used for diagnosing and treating small bowel diseases for over two decades. Insertion depth is a key quality indicator for enteroscopy performance. Although several adjunctive techniques have been introduced to enhance insertion depth, including carbon dioxide insufflation, transparent cap attachment, and water exchange method, operator proficiency consistently remains the most critical determinant of procedural success.

Single-balloon enteroscopy (SBE), through design optimization, offers simplified operation and a shorter learning curve compared with the double-balloon enteroscopy (DBE). Nevertheless, its procedural approach has not been revised. Clinical practice guidelines recommend the conventional two-operator technique originally established for DBE. In this setting, suboptimal coordination between the endoscopist and assistant, particularly with respect to timing and force modulation during overtube advancement and withdrawal, may not only substantially compromise insertion depth but also increases the risk of procedural complications.

Single-operator enteroscopy technique has been previously described reported. Independent control of both the enteroscope and overtube by a single operator theoretically maximizes instrumental flexibility, potentially conferring significant advantages in technical maneuvers and loop reduction. Furthermore, this approach may reduce procedure duration and optimize endoscopy unit staffing efficiency. Nevertheless, whether the single-operator technique compromises enteroscopy performance-particularly insertion depth, a primary determinant of diagnostic yield-has not been rigorously evaluated.

We therefore designed a multicenter, randomized controlled non-inferiority trial to compare single-operator versus two-operator technique with respect to insertion depth and lesion detection rate during single-balloon enteroscopy.

Inclusion Criteria:

• age greater than eighteen years;
• suspected small bowel disease with planned enteroscopy

Exclusion Criteria:

• patients with a history of small bowel surgery;
• patients who fail to perform bowel preparation as required;
• patients with existing esophageal varices at high risk of bleeding;
• patients not requiring a deep small-bowel examination, such as those with lesions clearly localized to the proximal jejunum, or terminal ileum;
• patients who are in extremely poor physical condition and are not suitable for general anesthesia, as defined by an ASA score greater than 3;
• pregnant or lactating women;
• patients unable to provide written informed consent.