Gall bladder removal and high blood sugar?

2 years ago my wife had her gall bladder removed. She had pancreatitis as well. Before she was admitted, she was diagnosed with diabetes. Today, she saw the doctor and mentioned her history from two year ago. The doctor had just seen a patient who had a gall bladder removed that was also diagnosed as being diabetic. When this patient took the medication her blood sugar levels dropped to unsafe levels. The doctors concluded that she was not in fact diabetic. My wife did not have this dramatic of a reaction, but the doctor retested her, and concluded that she was not a diabetic. Any insight into this?