PurposeThe aim of this study was to describe our treatment experiences with patients who had acute abdomen (AA) with common bile duct (CBD) dilatation.MethodsThe treatment outcomes in children with AA and CBD dilatation were retrospectively reviewed. According to the shape of the intrahepatic bile ducts on ultrasonography (US), the origin of the pain was estimated as choledochal cyst (CC) complication or choledocholithiasis in normal CBD. Patients with complicated CC underwent surgery, and patients with choledocholithiasis in a normal appearing CBD underwent symptomatic treatment initially.ResultsOf the 34 patients, 30 (88.2%) were female. The mean age of the patients was 6.4±4.9 (range, 0.8–17) years. Seventeen (50.0%) patients had CBD stones and 17 (50.0%) did not. Surgical treatment was performed in 20 (58.8%) patients, 2 of whom underwent preoperative stone removal with endoscopic retrograde cholangiopancreatography and an operation. Conservative treatment was applied in 12 (35.3%) patients (8 with and 4 without stones), 1 of whom developed symptom relapse and underwent an operation. Among the 8 patients with CBD stones, 4 (4/17, 23.5%) had complete resolution of the stones and recovery of the CBD diameter after conservative treatment. US findings of patients with stone showed a fusiform or cylindrical shape of the CBD in 14 (82.4%) patients.ConclusionThe presence of stones in the distal CBD and the US features of CBD dilatation may be helpful to diagnose and treat the causes of biliary dilatation. Conservative treatment can be considered as initial therapy in patients with uncomplicated CBD dilatation with stone.