To test the benefits of extra high carbohydrate liquid diet uptake 2 hours before ERCP in improving patients' early recovery.

Enhanced recovery after surgery (ERAS) has been formed of procedure which contains preoperative education, improvement of anesthesia, reducing the number of drainage tubes, and early diet after surgery. In recent years, because of its positive advantages, ERAS was widely accepted in surgical fields.

For upper gastrointestinal surgery, high-carbohydrate drinks can be given 2 hours before surgery in order to guarantee the stability of blood glucose and circulation during the operation. It obviously reduce the preoperative thirst, hunger, irritability and even the incidence of postoperative complications.

However ERAS program is rarely studied in ERCP. Theoretically we can use ERAS as a strategy to reduce post-ERCP uncomfortable and complications.

Inclusion Criteria:

• ERCP patients,
• Age 18-85 years old.

Exclusion Criteria:

• Coagulation dysfunction (INR> 1.3) and low peripheral blood platelet count(<50×109 / L) or using anti-coagulation drugs,
• Preoperative coexistent diseases: acute pancreatitis, GI tract hemorrhage, severe liver disease, shock, liver or kidney malfunction,
• Diabetes（blood glucose fluctuations）or with complications,
• Intestinal obstruction or other contraindications with feeding and watering,
• Prior surgery of Bismuth Ⅱ and Roux-en-Y,
• Pregnant women,
• Unwillingness or inability to consent for the study.