Review Question - QID 214562

A 7-year-old boy presents to the emergency department with abdominal pain. He states that his pain started this morning after eating chocolate cake for breakfast. The child has no fevers, chills, nausea, vomiting, or diarrhea. He had a case of septic shock at age 4 from pneumonia that required a 1-week stay in the intensive care unit. Since the child's discharge from the intensive care unit 3 years prior, he has been brought to the emergency department and primary care office frequently by his parents, who always seem genuinely concerned for his health. For example, on one visit the patient presented with a moderate non-productive cough likely associated with a viral illness, for which the parents demanded a chest CT scan. At another visit, the patient presented with several nosebleeds during the winter months, for which the parents demanded a hematology consult. At this visit, they are requesting gastroenterology evaluation and possible colonoscopy for his abdominal pain. His temperature is 97.5°F (36.4°C), blood pressure is 100/72 mmHg, pulse is 85/min, respirations are 15/min, and oxygen saturation is 98% on room air. Physical exam reveals a child playing with toys. His abdomen is non-tender and he is able to jump up and down and drink juice. Which of the following is the most likely diagnosis?