Ulcerative colitis is a condition that mainly affects young adults where the lining of the bowel is inflamed causing bloody diarrhea. The cause of ulcerative colitis is unknown and treatments remain imperfect with no cure for the disease. Initial success has been shown with a highly novel treatment where patients with active ulcerative colitis receive a fecal enema to try and replace their stool containing bacteria that may be driving their disease with that from a healthy donor. To assess if this works by comparing how well it treats the disease compared to a placebo enema.

Hypothesis Fecal biotherapy will be more effective than placebo at inducing remission in patients with active UC.

Approach and work plan Patients aged 18 or over with active UC defined as a Mayo score (13) more than 3 with an endoscopic score more than 0 will be eligible for the study. Subjects will be excluded if they are participating in another clinical trial, are unable to give informed consent, have severe comorbid medical illness, have concomitant Clostridium difficile infection or have severe UC requiring hospitalization. Continued treatment with 5-ASA, azathioprine, 6-mercaptopurine or anti-TNF therapy (e.g. infliximab) will be permitted if taken at stable dose for more or equal to 12 weeks prior to randomization. Eligible patients will be randomized to receive fecal biotherapy or placebo. Fecal biotherapy will be provided by an unrelated donor who is able to give informed consent, travel to the treatment centre at St Joseph's Hospital, Hamilton and able to collect fecal sample as needed for the fecal transplantation protocol. Fecal microbiome profiling will be carried out using both Roche 454 pyrosequencing and Illumina sequencing.

One hundred and thirty active UC patients will be randomized 1:1 according to a computer generated randomization list. Randomization will be administered centrally at the GI Clinical Trials Unit to ensure concealment of allocation. Eligible patients will be randomized to receive a weekly fecal biotherapy enema or a placebo enema for six weeks. In order to mitigate a placebo effect, both the patient and study staff will be blinded to the allocation of the treatment. An unblinded, independent laboratory technologist will prepare the retention enema according to the treatment arm to which the patient is assigned. The enema containers will be fully colour-tinted from the tip to the bottom of the container. The container will be placed inside a paper bag, which contains baking soda to absorb the odor. Both the patient and the study nurse will be required to wear a tightly fitted mask at all times during the infusion and retention of the enema.

Subjects will have a sigmoidoscopy (or colonoscopy if clinically indicated), physician assessment and complete a Mayo score (13) and IBDQ questionnaire (15) at baseline. The physician assessment, IBDQ and partial Mayo score (Mayo score without the sigmoidoscopy) will be repeated at 3 weeks. A repeat sigmoidoscopy, physician assessment IBDQ and Mayo score will be completed at 6 weeks, at exit from the study. No new medical therapies (e.g. corticosteroids, antibiotics, probiotics) will be permitted during the six-week study period. At the end of the treatment component of the study, fecal biotherapy will be offered to the participants in the placebo arm with clinical and sigmoidoscopic evidence of active UC.

Inclusion Criteria:

• Patients aged 18 or over with active UC defined as a Mayo score (13) more than 3 with an endoscopic score more than 0 will be eligible for the study
• Continued treatment with 5-ASA, azathioprine, 6-mercaptopurine or anti-TNF therapy (e.g. infliximab) will be permitted if taken at stable dose for more than or equal to 12 weeks prior to randomization.

Exclusion Criteria:

• Subjects will be excluded if they are participating in another clinical trial, are unable to give informed consent, have severe comorbid medical illness, have concomitant Clostridium difficile infection or have severe UC requiring hospitalization.