A patient comes to the emergency room with pain in his stomach and a history of irregular bowel movements. Which problem is most likely causing these symptoms? A. A problem with the digestive system, possibly irritable bowel syndrome B. A problem with the urinary system, possibly lactose intolerance C. A problem with the digestive system, possibly a kidney infection D. A problem with the urinary system, possibly constipation Please select the best answer from the choices provided. A B C D.