Objective To observe the clinical application effects of intravenous anesthesia with low-dose esketamine combined with propofol on painless colonoscopy for children.Methods 112 children who underwent painless colonoscopy in Huai’an Maternal and Child Health Hospital from September 2020 to May 2022 were selected as the research subjects, and were divided into group A (n=37), group B (n=38) and group C (n=37) according to the random number table method.The children in group A adopted intravenous anesthesia with 0.3 mg/kg of esketamine combined with 2.0 mg/kg of propofol, the children in group B received 0.2 μg of sufentanil+2.0 mg/kg of propofol for intravenous anesthesia, and the children in group C were given intravenous anesthesia with 2.0 mg/kg of propofol alone and then injected with the same volume of normal saline as esketamine in group A.The success rate of first-dose anesthesia, operation time, anesthesia awakening time, pain and emergence agitation and pain stress response were compared between the two groups.After 24 h of follow-up, the occurrence of adverse reactions after anesthesia in the three groups were statistically analyzed during follow-up.Results The success rate of first-dose anesthesia in group A was higher than that ingroup B and group C, and the colonoscopy operation time and awakening time were shorter than those in group B and group C (P＜0.05).There was no statistical significance in the score of Faces, Legs, Activity, Cry and Consolability (FLACC) among the three groups after 5 min of anesthesia (T1) (P＞0.05).After 15 min (T2) and 25 min (T3) of anesthesia, the FLACC scores were lower in group A than those in groups B and C (P＜0.05).The scores of Pediatric Anesthesia Emergence Delirium Scale (PAED) in group A at 10 min (T4) and 20 min (T5) after the end of the examination were lower than those in groups B and C (P＜0.05), and there was no statistical difference in the PAED score at 30 min (T6) after the end of the examination among the three groups (P＞0.05).There were no statistical differences in heart rate (HR), mean arterial pressure (MAP) and blood oxygen saturation (SPO2) among the three groups before administration (T7) (P＞0.05).During colonoscopy across hepatic flexure (T8), colonoscopy across splenic flexure (T9) and at the end of examination (T10), the HR level of group A was higher than that of group B and group C (P＜0.05), but there was no statistical difference in the level of SPO2 among the three groups (P＞0.05).There was no statistical significance in the proportion of MAP decline at T7 among the three groups (P＞0.05).At T8, T9 and T10, the proportion of MAP decline in group A was lower than that in group B and group C (P＜0.05).There were no statistical differences in adverse reactions after anesthesia among the three groups (P＞0.05).Conclusion Low-dose esketamine combined with propofol has accurate anesthesia effects in pediatric colonoscopy, and it can shorten the operation time, relieve the pain and stress response and promote the early awakening of children, with certain safety