A 3-year-old girl presents with a 2-day history of fever, vomiting, and bloody diarrhea. On examination, she appears lethargic and has a distended abdomen with tenderness. Her stool culture grows Shigella dysenteriae. Laboratory results reveal hemoglobin of 9.5 g/dL, platelets of 90,000/µL, and serum creatinine of 1.6 mg/dL. What is the most likely complication in this child?