A 54-year-old male patient named D.N. developed type 2 diabetes mellitus (T2DM) 10 months ago. At the time, he weighed 225 pounds and had a body mass index of 35.2. D.N. was started on metformin with poor control and, within two months, glimepiride was added to his regimen. Six months later, D.N.'s hemoglobin A1c (HbA1c) was still above 8% (normal is less than 6%), so his endocrinologist added exenatide. He had a fairly well controlled fasting blood glucose and HbA1c ranging from 6.5%-7.3% after exenatide was added. One month later, however, D.N. developed abdominal pain and anorexia with a 20-pound weight loss. His blood glucose became extremely labile despite his poor oral intake and good compliance with his oral hypoglycemic agents.