The gallbladder cannot grow back once it has been surgically removed. In some cases, when the gallbladder is diseased or causing severe issues such as gallstones, doctors may recommend a procedure called cholecystectomy to remove it. Once removed, the gallbladder does not regenerate.
https://lifewithnogallbladder.com/can-gallbladder-grow_back/
https://lifewithnogallbladder.com/can-gallbladder-grow_back/