Manipulating the Microbiome in IBD by Antibiotics and FMT

Inclusion Criteria: * Children over the age the 2 years and adults of all ages with established diagnosis of UC using standard criteria (26, 27). * Admission for IV steroid therapy * PUCAI of at least 65 points at admission (i.e. severe attack) * PUCAI\>45 at enrollment * Ability to swallow antibiotics (pills or syrup) Exclusion Criteria: * Change in dose or intervals of anti-TNF within the past 2 months prior to admission. * Disease confined to the rectum (Proctitis). * Antibiotic use in the past 4 weeks. * Any known erosive inflammation anywhere in the small bowel or esophagus. * Any proven infection such as positive stool culture, parasite or C. difficile, urinary tract infection, cellulitis, abscess, pneumonia, line-infections etc. * Fever \>38.5, or \>38.0c thought to be unrelated to the inflammatory process of active UC. * The probable need for second line medical therapy (infliximab, cyclosporine, tacrolimus) or colectomy within 5 days of enrollment, as judged by the caring physician. * Known allergy to more than one antibiotic regimen from the list below. * Pregnancy.