Here is the design of a clinical trial:

Official Title: Randomized Controlled Trial of Fecal Microbiota Transplantation in Severe Obesity

Included conditions:
- Obesity, Morbid

Study Armgroups:
- {'label': 'Intervention', 'type': 'ACTIVE_COMPARATOR', 'description': 'Active Comparator. Transplant from Donor A or Donor B, or Donor C or Donore D, one transplant consist of 50-80g of feacal matter.', 'interventionNames': ['Other: Fecal microbiota transplantation']}
- {'label': 'Placebo', 'type': 'PLACEBO_COMPARATOR', 'description': 'Placebo. Patient will recieve an autologous fecal microbiota transplantation.', 'interventionNames': ['Other: Placebo: fecal microbiota transplantation']}

Interventions:
- {'type': 'OTHER', 'name': 'Fecal microbiota transplantation', 'description': 'The intervention treatment is fecal microbiota transplantation made of frozen donor feces. The FMT is transferred as rectal enema where we use a rectal probe with a balloon to prevent leakage and keep the solution long enough in the colon. The patient will stay on the bench in different positions for 20 minutes. We will encourage the participant to keep the solution in the colon as long as possible and give them four pills of loperamide before the procedure in order to reduce bowel motility.', 'armGroupLabels': ['Intervention']}
- {'type': 'OTHER', 'name': 'Placebo: fecal microbiota transplantation', 'description': 'The placebo group get fecal microbiota transplantation made of their own feces. The FMT is transferred as rectal enema where we use a rectal probe with a balloon to prevent leakage and keep the solution long enough in the colon. The patient will stay on the bench in different positions for 20 minutes. We will encourage the participant to keep the solution in the colon as long as possible and give them four pills of loperamide before the procedure in order to reduce bowel motility.', 'armGroupLabels': ['Placebo']}

Primary Outcomes:
- {'measure': 'Change in individual weight loss (kg).', 'description': 'Partisipants will be measured at the outpatient clinic, medical department UNN Harstad, and weight in kilograms (kg) will be recorded. The data will be represented both as average weight change and as bar charts with \\>10%, with comparison between the intervention and control group.\n\nChi Square or Fischer exact test will be used to present responders and non-responders in the active and controll group. We will use odds ratio to present responders in the active group.', 'timeFrame': 'Change from baseline body weight at 12 months post FMT'}

Please estimate the sample size based on the assumption: 
The sample size calculation assumes a power of 0.90, a significance level of 0.05, and a high dropout rate of approximately one third. Extreme values more than 3 SD from the average will be eliminated.
Determination of sample size
        To determine the sample size, we looked at data from our outpatient clinic and found that patients have an average weight loss of 2.5% with our conservative treatment, SD near 7. This will therefore be the expected result in the control group (receiving placebo). A weight reduction of â¥10% leads to significant improvement in health and quality of life,14 and a weight change of this magnitude is therefore considered clinically relevant. The difference between the two groups is estimated to be 7.5%, and with these historical results, the sample size is estimated to be 19 participants in each group with a power of 0.90 and significance level of 0.05. We will eliminate extreme values, more than 3 SD out of the average in the group. We must be prepared for a high drgree of loss to follow-up (near one third), as this is the experience from the outpatient clinic for severe obesity.15 Therefore, we will include 60 participants, 30 in each group.