Could also be food intolerance for some ingretient.

The gallbladder itself isn’t super neccesary, as it only stores some extra bile in case more is needed. The bile itself is produced by the liver. That’s why you will notice its absence when you eat something very fatty (bile is used to break down fats).

Could be worth talking to a doc about. Checking your gallbladder for abnormalities is probably not much more than an ultrasound