I'm assuming your doctor told you to maintain a low-fat diet after having your gallbladder removed, so the Whole30 diet (being a higher fat diet) is surely not working for your body in this regard (bile secreted by the gallbladder is what helps break down fat).
A lot of excess fat in the digestive track leads to MAJOR diarrhea, which really is a potential answer for MANY of the old questions posted here.