Mothra has this type of pain which as far as I know wasn't gallstones but was some type of irritation. She controls the pain through diet. Very little grease means not irritating it.

Friend of hers had her gall bladder out bc of this type of pain, but Mothra has not had to do so and probably won't.

Go get yer shit checked. Is probably not a big deal, but knowing what you're working with is best.