Objective To investigate the effects of intravenous anesthesia with remimazolam tosilate and Propofol Injectable Emulsion（Limengxin） on postoperative cognitive function and recovery quality in patients receiving painless colonoscopy

so as to provide a reference for clinical diagnosis and treatment. Methods Eighty patients who underwent painless colonoscopy in the Yantai Yeda Hospital from January to August 2021 were selected as the study subjects. The patients were assigned to the control group and the observation group by the random number table

with 40 cases in each group. Patients in the control group were given intravenous sufentanil 1 ug/kg followed by intravenous Limengxin 1.5 mg/kg. Patients in the observation group were given an intravenous injection of 1 ug/kg sufentanil

followed by a slow intravenous injection of 0.2 mg/kg remimazolam tosilate. Diastolic blood pressure

heart rate

and respiratory trequeney were compared between the 2 groups until the completion of the procedure. Mini-Mental State Examination（MMSE） scores were compared between the two groups before anesthesia and during recovery. Recovery time was compared between the 2 groups. Adverse reactions were compared between the 2 groups from the start of anesthesia to 1 h of recovery. Results There was no significant difference in respiration

diastolic blood pressure

and heart rate before anesthesia

3 min after anesthesia

and at the end of examination between the two groups（P>0.05）. Before anesthesia

there was no significant difference in MMSE score between the two groups（P>0.05）. At recovery

the MMSE scores of patients in both groups were significantly lower than those before anesthesia

while those in the observation group were significantly higher than those in the control group（P<0.05）. The recovery time of the observation group was（6.85±0.35） min

which was significantly shorter than that of the control group（7.98±1.21） min（P<0.05）. The incidence rate of adverse reactions in the observation group was 2.50%

which was significantly lower than 22.50% in the control group（P<0.05）. Conclusion Intravenous anesthesia with Limengxin is as effective as remimazolam tosilate in providing effective sedation for patients receiving the colonoscopy

but the latter has higher medication safety and better postoperative recovery quality

which hold promise for a wider application of this technique.