Jung 2007.

Methods	Randomisation: central randomisation; random numbers. Blinding: none. Withdrawal/dropout: 14 (Group A), 12 (Group B): lost to follow up and data not submitted. Follow up: 30 days after surgery.
Participants	Inclusion criteria: participants undergoing elective open surgery for cancer, adenoma or diverticular disease of the colon, involving an anastomosis; aged between 18‐85 years with an ASA grade of I, II or III. Exclusion criteria (162 excluded): laparoscopic surgery; procedures involving a stoma; ASA scope IV and a life expectancy of less than 6 months. Diseases: cancer, adenomas, diverticular disease. Number: 1343 (623 male; 720 female) Age: 69 years (28‐86 years). Location of study: 1 German and 20 Swedish colorectal units. Date: January 1999‐March 2005. Antibiotics: oral sulphamethoxazole‐trimethoprim + metronidazole (46%); cephalosporin + metronidazole (33%); doxycycline + metronidazole (14%).
Interventions	Group A ‐ MBP (n = 686): PEG or sodium phosphate. Group B ‐ no preparation (n = 657).
Outcomes	Anastomotic dehiscence: Group A = 13, Group B = 17. Wound infection: Group A = 54, Group B = 42. Deep abscess: Group A = 5, Group B = 11. Reoperation: Group A = 30, Group B = 35. Wound disruption: Group A = 10, Group B = 13. Cardiovascular complications: Group A = 35, Group B = 30. General infections: Group A = 54, Group B = 45. Surgical site: Group A = 103, Group B = 106. Total number of complications: Group A = 192, Group B = 181.
Notes	A multicenter study. The groups were well matched with regard to age, sex and diagnosis. Surgeons in this study were all specialists in colorectal surgery. Intention‐to‐treat analysis. The sample size was calculated. The mean hospital stay was 9 days (7‐14 days). Extra data after stratification has been obtained in a personal communication with the author.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Low risk	A ‐ Adequate