Ciprofol is a new anesthetic, which combines with γ- Aminobutyric acid-a (GABAA) receptor. Ciprofol has shown equivalent anesthetic efficacy of propofol at 1/4 to 1/5 of the dosage. Ciprofol has the pharmacodynamic characteristics of rapid onset, stable and rapid recovery. Phase III clinical results showed that the incidence of injection pain and respiratory and circulatory depression of ciprofol was lower than that of propofol. Therefore, ciprofol has a good application prospect in sedation for gastrointestinal endoscopy, especially for obese patients. In the current study, we would explore the proper dose of Ciprofol in sedated gastrointestinal endoscopy in obese patients.

Inclusion Criteria:

1. Age, ≤18 and ≤60 years, no gender limit
2. Undergoing routine gastrointestinal endoscopic diagnosis and treatment
3. American Society of Anesthesiologists (ASA) classification I-II
4. Body Mass Index(BMI) ≥28kg/m^2
5. Clearly understand and voluntarily participate in the study; provide signed informed consent

Exclusion Criteria:

1. Unhealthy alcohol drinking, defined by more than three standard drinks per day (≈10 g alcohol , equivalent to 50 g of strong Chinese spirits)
2. Drug abuse history within 3 months before the screening period
3. People who are known to be allergic to eggs, bean products, opioids and other drugs, propofol, etc
4. The researcher believes that patients should not participate in this trial

We have no plan to share individual participant data.