The signs and symptoms of HUS may vary, depending on the cause. Most cases of HUS are caused by infection with certain strains of E. coli bacteria, which first affect the digestive tract. The initial signs and symptoms of this form of HUS may include: HUS HUS HUS 
Diarrhea, which is often bloody
Abdominal pain, cramping or bloating
Vomiting
Fever
 All forms of HUS — no matter the cause — damage the blood vessels. This damage causes red blood cells to break down (anemia), blood clots to form in the blood vessels and kidney damage. Signs and symptoms of these changes include: HUS 
Pale coloring, including loss of pink color in cheeks and inside the lower eyelids
Extreme fatigue
Shortness of breath
Easy bruising or unexplained bruises
Unusual bleeding, such as bleeding from the nose and mouth
Decreased urination or blood in the urine
Swelling (edema) of the legs, feet or ankles, and less often in the face, hands, feet or entire body
Confusion, seizures or stroke
High blood pressure
  When to see a doctor See your doctor immediately if you or your child experiences bloody diarrhea or several days of diarrhea followed by: 
Decreased urine output
Swelling
Unexplained bruises
Unusual bleeding
Extreme fatigue
 Seek emergency care if you or your child doesn't urinate for 12 hours or more.