Efficacy of Simethicone and N-Acetylcysteine in Improving Gastric Mucosal Visibility During Upper Gastrointestinal Endoscopy

Background: Gastric mucus and foam can obscure the mucosal surface during upper gastrointestinal endoscopy, potentially limiting visualization. Premedication with simethicone or N-acetylcysteine (NAC) may improve mucosal visibility. The aim is to compare the effectiveness of simethicone and NAC with placebo in improving gastric mucosal visibility during upper gastrointestinal endoscopy. Materials and Methods: This randomized, double-blind, placebo-controlled study included 2,234 patients undergoing upper gastrointestinal endoscopy at the Department of Gastroenterology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar. Participants received 100 mL water (placebo; Group A, n=832), simethicone 100 mg in 100 mL water (Group B, n=708), or NAC 600 mg in 100 mL water (Group C, n=694), approximately 15–30 minutes before endoscopy. Gastric visibility was assessed using the total mucosal visibility score (TMVS); lower scores indicated better visibility. Results: Mean age was 44.5±16.02 years (range 5–98); 1,161 (51.97%) participants were male and 1,073 (48.03%) female. Rural residents accounted for 1,349 (60.38%) and urban residents for 885 (39.62%). Mean TMVS was 9.49±1.913 in Group A, 5.27±1.527 in Group B, and 7.43±1.676 in Group C; the overall difference was significant (p<0.001). Pairwise mean differences were 4.22 for A versus B, 2.06 for A versus C, and −2.16 for B versus C (all p<0.001). Gender and residence distributions did not differ significantly across groups (p=0.544 and p=0.637, respectively). Conclusion: Simethicone produced the best gastric mucosal visibility, followed by NAC, while placebo had the highest TMVS. Simethicone may be a useful premedication before upper gastrointestinal endoscopy.