Water-assisted colonoscopy (WAC) has gained attention over the past decade as a technique that may enhance patient comfort, reduce sedation needs, and potentially improve mucosal visualization compared with conventional gas insufflation. Despite its advantages, widespread adoption in daily practice remains limited. The aim of this study was to evaluate the real-world performance, safety and feasibility of implementing WAC as the default method for routine colonoscopy in a high-volume endoscopy unit.

This prospective observational study included all consecutive colonoscopies performed with the water-assisted technique over a 12-month period. A total of 487 examinations were analyzed. Data collected included cecal intubation rate (CIR), total procedure time, propofol dose, adenoma detection rate (ADR), patient-reported tolerance and adverse events. The feasibility and safety of underwater polypectomy during WAC were also assessed.

Cecal intubation was achieved in all examinations (100%), demonstrating the technical reliability of the method even in a mixed screening and diagnostic population. The mean total procedure time was 12.6 ± 3.5 minutes, clearly shorter than commonly reported times for standard air or CO₂ insufflation techniques. Sedation requirements were remarkably low, with a mean propofol dose of 35 ± 10 mg. Nearly one quarter of patients (23.8%) required only minimal sedation (<20 mg). These findings highlight one of the most practical advantages of WAC in real-world settings: significantly reduced medication use and faster post-procedural recovery. The overall ADR was 45.8%, a performance level consistent with high-quality colonoscopy practice and comparable to or superior to previously published WAC data. The clear water-filled lumen and buoyancy-induced stabilization of mucosal folds appeared to assist in the visualization of flat or subtle lesions. Underwater polypectomy was performed in 67 polyps, mainly flat or sessile lesions up to 25 mm. In approximately 75% of these cases, no submucosal injection was required due to the lifting effect created by the water column, which facilitated safe and controlled resection. Safety outcomes were excellent. No perforations or delayed bleeding events occurred, and overall complications were negligible. Mild, transient post-procedural abdominal discomfort was reported in only 2.4% of patients. Patient satisfaction was high, with 96% rating the experience as “excellent” or “very good,” largely attributed to minimal discomfort, reduced cramping and decreased need for sedation.

In conclusion, water-assisted colonoscopy can be successfully incorporated into the daily workflow of a modern endoscopy unit, offering significant advantages over conventional colonoscopy. The technique was associated with shorter examination times, minimal propofol requirements, high adenoma detection rates, excellent patient tolerance and an extremely low complication profile. These real-world findings support the broader adoption of WAC as an efficient, patient-friendly and high-quality method for routine colonoscopy.