UGI endoscopy(esophagogastroduodenoscopy) is the main diagnostic modality for direct visualization ,real time assessment and interpretation of findings encountered. The evaluation of esophagogastroduodenoscopy (EGD) quality measures encompasses several categories, such as structure, procedure, result, and adverse events. The peri-EGD period procedures fall under the procedural area, which is primarily concerned with preventing and minimising missed diagnoses.

. More aid in the identification and characterisation of gastrointestinal mucosal lesions is provided by endoscopes equipped with improved imaging technologies, such as multiband or narrow-band imaging (NBI). Despite these advancements of technological aspects, the unclean mucosal surface of the stomach can make these high-end pieces of equipment virtually useless To visualize properly and diagnose accurately there should be clear visibility of mucus apart from operator experience. Since the stage at diagnosis of upper gastrointestinal cancer is a major factor in survival, early detection is essential in improving the prognosis of patients the main factors responsible for hinderance of mucosal visibility are mucus foam and bubbles, which requires additional care for the clearance to enhance the vision and also decrease endoscopy duration by alleviating the need of repeated flushing and suctioning during endoscopy. The froth and bubbles are made of mucous secretions mixed with gastric juice and bile. Simethicone (polydimethylsiloxane and silicon dioxide) has been proven to be a promising defoaming agent as an endoscopic premedication in removing bubbles . Simethicone works by reducing the surface tension of air bubbles, and releases the trapped air by causing small bubbles to coalesce and collapse . N-acetylcysteine (nac), a mucolytic agent, has also been used as premedication acts by removing the mucous overlying the gastrointestinal mucosa 4-point scale described by Basford et al

1. No adherent mucus and clear views of the mucosa.
2. A thin coating of mucus that did not obscure views of the mucosa.
3. Some mucus/bubbles partially obscuring views of the mucosa (i. E. A small mucosal lesion might be missed without flushing
4. Heavy mucus/bubbles obscuring views of the mucosa (i. E. Extensive flushing is needed to avoid missing small mucosal lesions)

Procedure

• Premixed medication (150mg simethicone and 600mg nac with 100ml of water) was given at specified timing Primary objective - comparison of mucosal visibility between 4 groups Secondary objectives - adverse events adequate gastric mucosal visibility lesion detection rate

Inclusion Criteria:

Age >18years

Exclusion Criteria:

• History of upper gastrointestinal surgery
• Neurological disorders with impaired swallowing
• Active gastrointestinal bleeding,
• Caustic ingestion
• Pregnancy.
• Known history of multiple allergies
• Gastric outlet obstruction
• Esophageal motility disorders
• Contraindication for upper GI endoscopy