This study aims to evaluate the effectiveness of sedation and analgesia in the treament of colorectal polyps by colonoscopy.

Colorectal polyps are precancerous lesions of the colorectal cancer. Colonoscopy can reduce the risk of colorectal cancer. Painless endoscopy could reduce patient discomfort and improves the acceptance of treatment, especially for the endoscopic treatment of colorectal polyps. Intravenous anesthesia colonoscopy has a strong sedative effect and has obvious inhibitory effects on the respiratory and circulatory systems. It requires the assistance of an anesthesiologist. The lack of anesthesiologists makes it difficult to make an appointment for anesthesia colonoscopy, which is a bottleneck in the diagnosis and treatment of gastrointestinal diseases in China. Therefore, there is an urgent need to find a painless diagnosis and treatment method that is not inferior to anesthesia colonoscopy in comfort to meet the needs of patients. Comparing to anesthesia colonoscopy, sedative and analgesic colonoscopy have similar sedative and analgesic effects and do not require the assistance of an anesthesiologist. However, there is no relevant evaluation on the effectiveness of sedation and analgesia during the endoscopic treatment of colorectal polyps. Our department has used midazolam combined with dezocine to treat 185 patients with colorectal polyps in these years. Retrospective analysis showed that the sedative and analgesic effect is satisfactory. Therefore, it is necessary to make a single-center randomized parallel group controlled non-inferiority study to directly compare the effectiveness of sedation and analgesia versus intravenous anesthesia in endoscopic treatment of colorectal polyps.

Inclusion Criteria:

• Colonoscopy diagnosed as a colorectal polyp, the number of polyps is less than 5, and the size of single polyp is less than 2.0 cm
• Age more than 18 years and less than 70 years

Exclusion Criteria:

• Allergy to propofol, dezocine, midazolam or eggs
• ASA class IV, short and tick neck, difficult intubation due to inability to open the mouth widely
• Suspected of gastrointestinal perforation, bleeding or obstruction
• Acute gastrointestinal infection period
• History of abdominal surgery
• Patients during pregnancy or lactation