A 42-year-old woman with diabetes mellitus type 2 treated with the sodium–glucose cotransporter-2 inhibitor canagliflozin underwent elective bariatric gastric bypass. The canagliflozin was held for 24 hours preoperatively. She physiologically decompensated on postoperative day 2. Ultimately, she was diagnosed with euglycemic diabetic ketoacidosis that required intensive care management. This diagnosis was challenging to make as the patient never became hyperglycemic. We use this case to discuss the pharmacology and potential risk of perioperative sodium glucose cotransporter-2 inhibitor administration and to advocate for revision of current guidelines regarding the perioperative management of these agents.