Choledochal cyst is a more common biliary tract disease in Asian children. Many children have huge cysts or acute obstruction at the distal end of the cyst, which leads to acute inflammation and dilation of the bile duct, resulting in biliary perforation. With a perforated choledochal cyst, a large amount of bile enters the abdominal cavity, which can lead to the formation of peritonitis, serious infections, etc. The child sometimes falls into a coma, and if not resuscitated in time, the child’s life can be in danger. The most effective treatment for perforated choledochal cyst, besides anti-inflammatory, rehydration and correction of electrolyte disorders, is to perform external biliary drainage and put a T-tube in the bile duct to remove bile directly from the body, so that bile will not enter the peritoneal cavity again and cause peritonitis. Because of the perforation, inflammation of the abdominal cavity, intra-abdominal edema inflammation, if this time to perform radical choledochal cyst surgery? the child bleeds a lot, trauma, cyst complete removal is difficult, coupled with its own child infection heavy, weak body, surgery risk is great. Therefore, it is generally recommended to perform external biliary drainage, bring down the inflammation, the child recovers a bit, drainage for 1-3 months, and then perform cystectomy. While waiting for radical surgery, postoperative care is extremely important. In clinical practice, we often encounter children who are extremely sick after external biliary drainage, and some of them are even critically ill. It takes several days of resuscitation to recover from coming to the hospital. The care precautions for external bile drains: 1, pay attention to the child to replenish electrolytes, to put it plainly is to give the child to replenish potassium sodium calcium chloride. Our normal human bile is rich in potassium, sodium, calcium, chloride and other electrolytes, and most of them are absorbed by our intestines after our bile is discharged into the intestines. In children with external biliary drainage, 200-800ml of bile is removed from the body every day, so all kinds of electrolytes in the bile are lost, and it is difficult to replenish them by eating. What is the problem of electrolyte disorder? The child will have deep sunken eyes, no tears from crying, poor mental status, weakness of limbs, drowsiness, cardiac arrhythmia, and in serious cases, it may be life-threatening. How to solve this problem? The oldest solution is to take the bile from the drainage bag and have the child drink it all in. This is outrageous, but effective, but after all, bile is very bitter and not very hygienic when drained into the drainage bag. Therefore, if you have the conditions, you can buy oral rehydration salts, the kind of oral rehydration salts for diarrhea, which can be prepared into a large jar of water according to the instructions, and let the child drink 400-500ml of water every day, or more if the bile drainage is large. This will keep the electrolyte balance. 2.How does the child eat? Because the child cannot eat before the operation, especially when the bile drainage is not good, the doctor does not allow to eat greasy, many parents after the drainage operation, give the child a little soup, resulting in the child yellow and thin, weight does not grow, coupled with the consumption of disease, the child after the operation is not better than before, but also more and more thin. This is not only detrimental to the child’s recovery but also to the second choledochal cystectomy. What is the right thing to do. If the child recovers well after surgery and the amount of drainage is sufficient every day, then the child can gradually resume the diet, and within a week the child can return to a normal diet and eat normally, meat, eggs and milk are no problem. This way the child will get stronger and stronger and recover faster from the next surgery.