The goal of this clinical trial is to compare the safeness and effectiveness of traditional esophagogastroduodenoscope (EGD) and wired magnetically assisted capsule endoscopy (MACE) in the diagnosis of esophageal varices in biliary atresia (BA) patients. The main questions it aims to answer are: * Subjects who do wired magnetically assisted capsule endoscopy do not need to open the mouths during the process, this study also want to know whether wired magnetically assisted capsule endoscopy can reduce the generation of droplets. * Diagnostic accuracy between traditional esophagogastroduodenoscope and wired magnetically assisted capsule endoscopy in biliary atresia patients with esophageal varices. Participants will do either traditional esophagogastroduodenoscope or wired magnetically assisted capsule endoscopy.