Fa‐Si‐Oen 2005.

Methods	Central trial office of randomisation, computer generated. Concealment OK. Blinding: not described. Withdrawal/dropout: no exclusions. Follow up: 3 months.
Participants	Inclusion criteria: elective colon surgery. Exclusion criteria: previous radiotherapy and/or chemotherapy; idiopathic inflammatory bowel disease; obstructive tumours; emergency laparotomy; MBP one week before the surgery; ileocaecal resections and resections below the peritoneal reflection. Diseases: recurrent diverticular disease, colon malignancy, other. Number: 250 (114 male; 136 female). Age: 27.7‐89.0 years. Location: 5 centres in the Netherlands (4) and Belgium (1). Date: 1 October 1998‐1 October 2002. Antibiotics: cefazolin (2 g) + metronidazole (1.5 g) or gentamicin (240 mg) + metronidazole (1.5 g), 30 minutes before surgery.
Interventions	Group A ‐ MBP (n = 125): 4 litres of PEG. Group B ‐ normal meal up to ten hours before surgery (n = 125).
Outcomes	Anastomotic leakage: Group A = 7, Group B = 6; Wound infection: Group A = 9, Group B = 7. Reoperation: Group A = 13, Group B = 11.
Notes	Primary data. Multicentre study. Sample size was calculated. All participants were included as intention to treat.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Low risk	A ‐ Adequate