The investigators examined the outcome of patients with severe Enterohaemorrhagic E. Coli (EHEC) O104:H4 infection suffering from bloody diarrhoea that were at risk to develop hemolytic uremic syndrome and underwent repetitive whole bowl lavage during hospitalization.

During the 2011 German EHEC O104:H4 outbreak, centered in the area of Hamburg, 33 patients with EHEC associated hemorrhagic colitis were admitted to the first Department of Medicine of the Hamburg University medical centre.

The first 12 patients were treated symptomatically and received intravenous rehydration up to three liters daily.

Prompted by a good clinical response after whole bowel irrigation with polyethylene glycol-solution (PEG)in patient 13 all subsequent admitted patients (n=21) were treated with PEG-solution ( 2 liters on admission followed by one liter per day during the clinical course).

During the hospital course blood work was obtained every day and patients were examined for clinical symptoms.

Thrombocytopenia below 100.000/microliter was defined as a threshold for initiating therapeutic plasmapheresis to prevent the onset of hemolytic syndrome on an early stage.

Inclusion Criteria:

• Proven EHEC O104:H4-infection

Presence of bloody diarrhoea + at least one of the following serological criteria:

• platelet count below 150x10³/ μl but greater than 100x10³/ μl, serum creatine above normal level for age (> 1.1 -1.3 mg/dl), Lactate dehydrogenase (LDH) > 300 IU/l, leukocytosis ( > 12x10³/ μl ) and elevated CRP (> 5mg/l), hemoglobin < 13.8 g/dL for male patients or < 12.1 g/dL for female patients, respectively or decrease in haptoglobin

Exclusion Criteria:

• Bloody diarrhoea due to others reasons than EHEC O104:H4 infection
• Thrombocytopenia < 100x10³/ μl.
• HUS, defined as platelet count below 100x10³/ μl, anaemia or decrease in haptoglobin and serum creatine above normal level for age