Here is the design of a clinical trial:

Official Title: Mechanical Bowel Preparation and Oral Antibiotics Versus Mechanical Bowel Preparation Only Prior Rectal Surgery - a Prospective, Randomized Controlled Trial

Included conditions:
- Rectal Adenocarcinoma
- Rectum Neoplasm
- Rectum Carcinoma
- Colorectal Cancer
- Colorectal Neoplasms
- Colorectal Carcinoma
- Surgical Site Infection
- Surgery--Complications

Study Armgroups:
- {'label': 'Mechanical Bowel Preparation and Oral Antibiotics', 'type': 'EXPERIMENTAL', 'description': 'Mechanical Bowel Preparation and Oral Antibiotics', 'interventionNames': ['Drug: Oral Antibiotics', 'Drug: Mechanical Bowel Preparation']}
- {'label': 'Mechanical Bowel Preparation Only', 'type': 'ACTIVE_COMPARATOR', 'description': 'Mechanical Bowel Preparation Only', 'interventionNames': ['Drug: Placebo', 'Drug: Mechanical Bowel Preparation']}

Interventions:
- {'type': 'DRUG', 'name': 'Oral Antibiotics', 'description': 'Oral antibiotics (neomycin 1g and metronidazole 1g at 3pm and 11pm the day before surgery)', 'armGroupLabels': ['Mechanical Bowel Preparation and Oral Antibiotics']}
- {'type': 'DRUG', 'name': 'Placebo', 'description': 'Oral placebos (placebo 1 and placebo 2 at 3pm and 11pm the day before surgery)', 'armGroupLabels': ['Mechanical Bowel Preparation Only']}
- {'type': 'DRUG', 'name': 'Mechanical Bowel Preparation', 'description': 'Mechanical Bowel Preparation using 2L polyethylene glycol (Moviprep)', 'armGroupLabels': ['Mechanical Bowel Preparation Only', 'Mechanical Bowel Preparation and Oral Antibiotics']}

Primary Outcomes:
- {'measure': 'Comprehensive Complication Index', 'description': 'Comprehensive Complication Index score', 'timeFrame': 'Within 30 days from surgery'}

Please estimate the sample size based on the assumption: 
The power is set at 90% and the margin of error at 5%. Approximately 5% of patients are estimated to become lost to follow-up.
Sample size calculation
        In Helsinki University Hospital, the number of leakages/abscesses related to low anterior resections performed in 2005â2011 was 12.8%, but minor wound complications were not reported.23 In our previous randomised MOBILE study comparing MOABP to NBP, patients undergoing colon resection had leakage/abscess rate of approximately 6%â8% and a CCI of 9â10 with SD 13â16.13 Based on these figures, we estimate that the CCI is higher in rectal surgery than in colon surgery and the SD may also be higher. Sample size was calculated with the aim of showing a difference of 5 CCI points between the groups (hypothesis: 12.5 points in the MOABP group, 17.5 points in the MBP group). The SD is estimated to be 18 in both groups. With a power of 90% and a margin of error of 5%, 574 patients need to be recruited (Willcoxon-Mann-Whitney test). About 5% of patients are estimated to become lost to follow-up, resulting in a final sample size of 604 patients.