This article discussed the diagnosis and management of acute GI bleeding, prophylaxis against GI bleeding, acute pancreatitis, and acalculous cholecystitis. These diseases are commonly encountered in the ICU setting. Acute GI bleeding is usually obvious and with GI and with available interventional radiologic techniques, patients rarely need surgery. Conversely, acalculous cholecystitis is difficult to diagnosis; therefore, a high degree of suspicion needs to be exercised with all critically ill patients.