To explore the correlation between gastric ultrasound evaluation and gastroscopic direct vision evaluation of gastric contents, so as to more accurately use gastric ultrasound to evaluate the gastric contents of patients undergoing painless electronic gastroscopy in the outpatient department, so as to develop an individual painless diagnosis and treatment strategy to reduce the risk of lung aspiration.

Inclusion Criteria:

• ≥18years
• Patients undergoing painless electronic gastroscopy.
• Voluntarily participate and sign informed consent.

Exclusion Criteria:

• Patients undergoing general electronic gastroscopy.
• Patients who refused to undergo gastric ultrasound.
• Patients with postural difficulties during gastric ultrasonography.
• with fresh wounds or infections at the site of Gastric ultrasound
• Patients whose ultrsound image quality is too poor to properly display the relevant anatomical structures.

Outpatients undergoing painless electronic gastroscopy were fasted for 8 hours in acccordance with gastroscopy guidelines