A 36-year-old male with a history of HIV presents to the ED complaining of dyspnea on exertion and fatigue. He is not compliant with his anti-retroviral medications. His conjunctivae are pale. There is a painful ulcer to the distal aspect of the tongue and scattered petechiae on his legs. Laboratory evaluation reveals WBC 2,000/microL, Hgb 8.5 g/dL, and platelets 90,000/microL. What do the exam and lab findings suggest?

32-year-old male presents to the ED with vomiting and abdominal cramping. He has Crohn's disease and has been poorly compliant with his medications. His current episode began as right lower abdominal pain 1 week ago with several episodes of watery diarrhea daily. He developed diffuse cramping, nausea and vomiting 2 days ago and has been unable to tolerate oral intake. He has not passed stool or flatus in 2 days. His abdomen is distended with hyperactive, high-pitched bowel sounds, increased tympany to percussion, and diffuse mild tenderness to palpation without rebound or guarding. What is the most likely diagnosis?