Does drinking alcohol have an effect on the gallbladder?

It can : It's an indirect effect, but the answer is yes. Liver makes bile Whichvis stored in the gallbladder. Alcohol effects the liver and can affect bile production. Alcohol also effects the pancreas which has a close interplay with the gallbladder too

No effect: Alcohol does not effect the GB. Rather in excess it effects sites it comes in contact with directly or indirectly. Here oral cavity lesions, esophageal lesions and gastriis are not uncommon. There is a secondary effect where patients who are alcoholic can develop severe pancreatitis.