During laparoscopic surgery for an acutely inflamed gallbladder, most surgeons routinely insert a drain. However, no consensus has been reached regarding the need for drainage in these cases, and the use of a drain remains controversial. This study is coordinated to find out the surgical outcomes and perioperative morbidity according to the insertion of drain after laparoscopic cholecystectomy. Investigators expect that the routine use of a drain after laparoscopic cholecystectomy for an acutely inflamed gallbladder will have no effects on the postoperative morbidity.