Ramosetron is effective in preventing postoperative nausea and vomiting. Several studies reported that ramosetron is also effective treatment diarrhea-predominant irritable bowel syndrome. The investigators examine the effect of ramosetron used for preventing postoperative nausea and vomiting on bowel motility.

Ramosetron, a new potent and long-acting selective 5-HT3 receptor antagonist, is effective for preventing postoperative nausea and vomiting. Also several studies reported that ramosetron is effective treatment of irritable bowel syndrome because it inhibits the accelerated colonic transit, abnormal colonic water transport, defecation abnormality, and the lowered colonic perceptual threshold by corticotrophin-releasing hormone. There is no study about the effect of ramosetron used for preventing postoperative nausea and vomiting on postoperative bowel motility. In this study, the investigators examine the effect of ramosetron on postoperative bowel motility.

Inclusion Criteria:

• 20-70 yr of age,
• ASA I or II,
• scheduled for laparoscopic colorectal surgery

Exclusion Criteria:

• antiemetic use within 24hr prior to surgery
• steroid use within 24hr prior to surgery or 48hr after surgery
• insulin dependent DM
• cardiovascular or pulmonary disease
• renal or hepatic insufficiency
• BMI >=35kg/m2
• pregnancy