What condition is indicated by a child presenting with bloody diarrhea, thrombocytopenia, renal failure, and hemolytic anemia with reticulocytes greater than 3%?

The presentation of a child with bloody diarrhea, thrombocytopenia, renal failure, and hemolytic anemia characterized by elevated reticulocyte levels greater than 3% strongly indicates Hemolytic Uremic Syndrome (HUS). This syndrome is often associated with an infection caused by certain strains of E. coli, particularly Enterohemorrhagic E. coli (EHEC), which can lead to the destruction of red blood cells and a decrease in platelet count due to the formation of microthrombi.

The combination of bloody diarrhea and subsequent renal impairment establishes HUS as a diagnosis because these symptoms typically arise following the gastrointestinal infection triggered by the bacteria. The presence of hemolytic anemia, reflected by a rise in reticulocytes, indicates the bone marrow's response to the destruction of red blood cells.

This condition is distinct from Thrombotic Thrombocytopenic Purpura (TTP), which has overlapping features like thrombocytopenia and hemolytic anemia but is characterized by neurological symptoms and a lack of a preceding diarrheal illness. Idiopathic Thrombocytopenic Purpura (ITP) primarily involves isolated thrombocytopenia without hemolytic anemia or renal failure, and Gl