High-quality bowel preparation is crucial for optimal colonoscopy performance. Simethicone, an anti-foaming agent, may enhance endoluminal visibility by reducing bubbles and foam, facilitating lesion detection and procedural efficiency.  The Aim of this study is to evaluate the effectiveness of adding simethicone to a standard polyethylene glycol (PEG) bowel preparation on colon cleansing quality, lesion detection, and procedural performance.

A prospective study was conducted from July to December 2024 in our Gastroenterology endoscopic Unit Eighty patients scheduled for elective colonoscopy were randomly assigned to two groups: Group A (n=40): Standard PEG 4L preparation Group B (n=40): Standard PEG 4L + simethicone 300 mg (administered with the last liter of PEG)Bowel preparation quality was assessed using the Boston Bowel Preparation Scale (BBPS). Secondary outcomes included adenoma detection rate (ADR), number of polyps detected per patient, need for intraprocedural lavage, cecal intubation time, and endoscopist satisfaction (Likert scale).

The mean age was 52 ± 13 years, with a sex ratio M/F of 1.2. Adequate bowel preparation (BBPS ≥ 6) was achieved in 33 patients (82.5%) in Group B versus 25 patients (62.5%) in Group A (p = 0.03). ADR was higher in Group B (28%) compared to Group A (16%) (p = 0.04), with a greater mean number of polyps detected per patient (1.8 ± 1.1 vs 1.1 ± 0.9, p = 0.02). The need for intraprocedural lavage was reduced in Group B (12.5%) versus Group A (30%) (p = 0.02). Cecal intubation time was slightly shorter in the simethicone group (7.2 ± 2.1 min vs 8.1 ± 2.5 min, p = 0.08), though not statistically significant. Endoscopist satisfaction scores were higher for Group B (median 4.5/5 vs 3.8/5, p = 0.01). No serious adverse events related to simethicone were reported.

Adding simethicone to standard PEG bowel preparation significantly improves colonic visibility, increases adenoma detection, reduces intraprocedural lavage, and enhances endoscopist satisfaction. This safe, low-cost intervention is recommended for routine colonoscopy protocols to optimize diagnostic outcomes.