S3233 Potassium in Peril: A Case of Acute Exocrine Pancreatic Insufficiency (EPI) Presenting as Persistent Hypokalemia

Introduction: Severe diarrhea can cause electrolyte imbalances, but persistent hypokalemia despite replacement is uncommon. This case highlights exocrine pancreatic insufficiency (EPI) as a rare cause requiring timely recognition and treatment. Case Description/Methods: A 78-year-old woman with a history of cholecystectomy and pacemaker placement presented with 10 days of profuse, non-bloody watery diarrhea—up to 20 episodes/day—unresponsive to loperamide. She denied fevers, GI bleeding, new medications or intensive care unit sick contacts. Labs revealed severe hypokalemia (K⁺ 2.7), magnesium 0.5, bicarbonate 6, anion gap 31, creatinine 9.8 (baseline 0.9) and normal liver enzymes. She was admitted to i for high anion gap metabolic acidosis, managed with bicarbonate drip, fluids, and electrolyte repletion. Renal function normalized, but hypokalemia persisted despite >2000 mEq of IV/PO potassium over 7 days. Upon further GI evaluation, computed tomography revealed an atrophic pancreas; stool studies showed low fecal elastase and osmotic diarrhea, confirming new-onset EPI. She was started on pancreatic enzyme replacement. Autoimmune and infectious workups were negative. Diarrhea improved gradually with enzyme therapy. Persistent hypokalemia was further attributed to concurrent type 1 RTA, and potassium citrate was initiated. She was discharged with ongoing potassium and enzyme supplementation. Discussion: EPI typically presents in the setting of chronic pancreatitis or pancreatic surgery, but this case underscores a rarer presentation with acute-onset diarrhea and severe, persistent hypokalemia in the absence of known pancreatic disease. This should raise concern for subclinical chronic pancreatitis or early pancreatic neoplasm—especially in elderly patients with no prior pancreatic history. EPI may also result from non-pancreatic conditions such as diabetes, aging, or celiac disease, and can lead to significant malabsorption, weight loss, and electrolyte disturbances. A high index of suspicion is required for EPI in patients with unexplained diarrhea and refractory electrolyte abnormalities, and considering malignancy when common etiologies are excluded.