Foam and bubbles can interfere with the detection of small or early lesions during esophagogastroduodenoscopy (EGD), prolong procedures, and increase complication risks. Pre-procedural preparation may reduce the need for mucus removal. This study evaluated the efficacy and safety of various pre-EGD preparation methods. Simethicone is known to reduce foam and improve visibility, though it may be less effective in patients with dense mucus, such as those with autoimmune or atrophic gastritis.

From July 2024 to July 2025, 192 patients aged 20–94 participated in a prospective, single-center, randomized, blinded study (Table 1). Exclusion criteria: prior gastrointestinal surgery, upper GI tract strictures, dysphagia, or allergy to premedications.

Premedication protocols:

Group A: no premedication

Group B: simethicone 40 ml

Group C: simethicone 20 ml + 5% sodium bicarbonate 20 ml

Group D: 5% sodium bicarbonate 20 ml

All solutions were administered 20 minutes before EGD.

Outcomes measured: mucosal visibility (GRACE scale), procedure duration, mucus removal time, and need for additional cleansing agents.

Group C (preparation with simethicone 20 ml + 5% sodium bicarbonate 20 ml) showed the shortest mucus removal time (20.8 seconds), highest GRACE score (6.7 in Group A vs. 8.4 in Group C), and the best subjective mucosal cleanliness, rated “excellent” in 88.9% of cases. The use of a combined preparation solution of simethicone and sodium bicarbonate demonstrated the highest efficiency in detecting pathological lesions – 51.1%, while the proportion of lesions less than 1 cm in size was 65.2%. 

The combination of sodium bicarbonate and simethicone is a safe, effective method to improve mucosal visibility during EGD and shorten procedure time, particularly in patients with dense mucus