Mr. Robert White, 73 years old, post-op day 2 abdominal surgery secondary to small bowel obstruction. Medical history includes HTN, DM 2, and right knee osteoarthritis. He has been NPO for 2 days due to the surgery. He has a nasogastric tube on low continuous suction. He reports feeling nauseous. He vomited 4 times yesterday and last night. What is Mr. white's primary medical problem and the causes of that problem?
