How we will distinguish between 90 % and 10% cases?

In childhood HUS

How we will distinguish between 90 % and 10% cases?

Since u said …bloody diarrhea is compulsory .

, but 10 % wont have bloody diarrhea.

Even if blood is not present, other parameters are taken into account, and diagnosis is made based on exclusion. The diagnosis of hemolytic uremic syndrome requires a high index of suspicion based on symptoms, travel history, and dietary history. A complete blood count (CBC), comprehensive metabolic panel (CMP), and a urinalysis may aid in the diagnosis. The CBC shows both anemia and thrombocytopenia. Hemoglobin is often less than 10 g/dl. A peripheral smear reveals characteristic schistocytes. The Coombs test is negative, consistent with mechanical hemolysis. The metabolic panel reveals elevated creatinine consistent with acute kidney injury. It also shows signs of acute hemolysis with elevated indirect bilirubin and elevated lactate dehydrogenase. As the disease progresses, hyponatremia and hyperkalemia may develop as the patient enters into renal failure. Urinalysis reveals hematuria and proteinuria. Thank you.