A 63-year-old Japanese woman with a remote history of a partial hysterectomy for fibroids was admitted to the general surgery service after 2 days of nausea, nonbloody emesis, and intermittent, crampy, epigastric pain. She denied any fevers, chills, cough, sore throat, dysuria, diarrhea, easy bruising, or rash. Born in Japan, the patient immigrated to the United States in 1973 and has lived in San Diego since that time. Travel history during the past 7 years included urban areas of Egypt, China, India, and Japan. The patient lived with her husband and had 2 cats. She denied any ill contacts. The findings of a physical examination were unrevealing, with the exception of diffuse abdominal tenderness to palpation without peritoneal signs or rebound. The results of laboratory tests performed at admission to the hospital revealed a WBC count of 8100 cells/mm3 with a differential cell count of 90% neutrophils, 6.7% lymphocytes, 2.6% monocytes, and 0% eosinophils; a hematocrit of 41.5%; and a platelet count of 233,000 platelets/mm3. The chemistry panel and liver function test results were normal except for a decreased total protein level of 5.6 g/dL (normal range, 6.1-7.9 g/dL), an elevated lactate dehydrogenase level of 204 IU/L (normal range, 99-192 IU/L), and an elevated amylase level of 494 IU/L (normal range, 36128 IU/L). A series of acute abdominal radiographic images revealed multiple dilated loops of small bowel with air-fluid levels consistent with partial small bowel obstruction. An abdominal and pelvic CT scan revealed the cause of the patient's abdominal complaints (figure 1). What is your diagnosis?