Review Question - QID 210821

An 8-year-old boy is brought to the pediatric emergency department by his parents with a complaint of abdominal pain and diarrhea for the past week. He states that for the past two days, he has noticed blood in his stool. His parents note that they attended a neighbor’s barbecue last weekend, but otherwise have not eaten any new foods or changed their usual diet. The patient is admitted to the hospital unit for further work-up. The provider team finds that the patient’s blood is positive for Shiga-like toxin and notes the following lab values: creatinine of 4.2 mg/dL, platelet count of 50,000/mm^3, and hemoglobin of 6.0 g/dL. Which of the following additional lab findings would be consistent with the diagnosis?