Endoscopic bile duct stone (BDS) removal is a well-established treatment; however, the preference for basket or balloon catheters for extraction is operator-dependent It is reported that complete endoscopic treatment with a single catheter is more likely when choosing a balloon catheter over a basket catheter for extraction of BDSs≤10mm. However, a study comparing the two catheter types in patients with periampullary diverticulum has not been performed, and there is no strong basis on which to recommend the balloon catheter as a first-line stone removal device. The investigators therefore conducted a multicenter prospective randomized trial to compare catheter performance in patients with periampullary diverticulum.

A prospective, multi-center, investigator sponsored, randomized controlled trial, 80 subjects will be randomly assigned to groups that were treated with basket or balloon catheters.

A descriptive analysis will be performed on primary endpoint, containing frequency of number and percentage of patients. A two proportion equality test will be conducted to explore whether incidence rates are different.Descriptive statistics including number (N), mean, median, standard deviation, minimum and maximum, will be produced for all continuous variables. Frequency tables of number (N) and percentage of subjects will be produced for all categorical variables.

Inclusion Criteria:

1. Males and females, age > 18 years.
2. BDSs of diameter ≤10mm, which could be extracted using a standard balloon or basket catheter without mechanical lithotripsy, and a common bile duct (CBD) diameter ≤15mm.
3. Signed inform consent form and agreed to follow-up on time

Exclusion Criteria:

1. Medical or psychological condition that would not permit the patient to complete the study or sign the informed consent.
2. Patients involved in other study within 60 days.
3. biliary stricture
4. Billroth II or Roux-en-Y anatomy
5. Acute pancreatitis.
6. a history of previous ERCP
7. pregnant or breastfeeding women