Celiac crisis, an atypical presentation of celiac disease, is characterized by acute diarrhea and severe metabolic derangements. This diagnosis is often missed in the differential of acute diarrheal illness. Our patient is a 69-year-old man who presented with ICD firing and was found to have profound metabolic derangements. Further evaluation revealed undiagnosed celiac disease and his symptoms resolved with a gluten-free diet. Celiac crisis should be considered in all patients presenting with acute diarrhea, metabolic acidosis, and severe electrolyte abnormalities as management can be life-saving.