Question: A 5-year old Caucasian boy presented with sudden onset of diffuse purpuric and petechial skin lesions without fever at the pediatric department. The following days he developed diffuse abdominal pain with bloody stools (4-6 times a day). He also complained of scrotal pain and joint pain (knee, ankles). His previous medical history was unrevealing. Family history was negative for autoimmune or gastrointestinal diseases. He had not taken medication besides paracetamol. Clinical examination revealed an alert but tachycardic boy with a blood pressure of 130/90 mm Hg. Pharyngeal aphthous lesions with slight facial edema and edema of the hands were noticed. Diffuse purpuric and petechial lesions of the face, arms, legs, buttocks, and abdomen were present. Auscultation of lungs and heart was normal. The abdomen was diffusely painful on palpation without rebound tenderness or guarding and without signs of organ (liver, spleen) enlargement. An enlarged and painful left scrotum was seen. His laboratory results showed: hemoglobin of 10.8 g/dL (reference, 11-14); leukocytes of 23.8 Â 10 3 /mL (reference, 6-14); platelets of 693 Â 10 3 /mL (reference,150-450); C-reactive protein of 57.5 mg/L (reference, <0.5); blood urea nitrogen of 24 mg/dL (reference, 12-42); serum creatinine of 0.29 mg/dL (reference, 0.32-0.59); total protein of 49 g/L (reference, 62-78); and albumin of 25 g/L (reference, 35-52). Electrolytes, coagulation times, liver enzymes, and lipase were within normal range but urinalysis showed nephrotic range proteinuria (3.6 g/L; reference, 0-0.2)), hematuria (4000/mL; reference, 0-25), and leukocuyturia (370/mL; reference, 0-25). Blood and urine cultures remained negative. Abdominal ultrasound showed no abnormalities of liver, kidneys, or spleen and with adequate peristalsis of the intestines. Ultrasound of the scrotum showed diffuse enlargement and hypervascularization of left epididymis consistent with epididymitis. Hematochezia persisted and 2 days after admission he suddenly developed severe colicky abdominal pain with reduced peristalsis. An abdominal radiograph was taken (Figure A) revealing an ileus. What is the most likely underlying diagnosis and which complication could the acute colicky abdominal pain with radiographic confirmation of an ileus represent? How would you explain the hematochezia? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI.