Van't Sant 2010.

Methods	It is a subgroup analysis of a prior large multicenter performed by Contant et al. Randomisation: computer‐generated randomisation list; participants were allocated to each intervention by means of numbered sealed envelopes that corresponded to the randomisation list. Blinding: none. Withdrawal/dropouts: not described. Follow‐up: first outpatients visit after discharge from the hospital which usually occurred after 2 weeks.
Participants	Inclusion criteria: elective low anterior resection with primary anastomosis. Exclusion criteria: acute laparotomy, laparoscopic colorectal surgery, contraindications for the use of mechanical bowel preparation, an a priori diverting ileostomy, and age less than 18 years old. Diseases: colorectal cancer, inflammatory bowel disease, other. Participants: 449 (no details about gender). Age: not described. Location of study: Netherlands (13 hospitals). Date: April 1998 ‐ February 2004. Antibiotics: according to the guideline of each hospital: cefuroxime + metronidazole, cefazolin + metronidazole, cefamandole + metronidazole, gentamycin + metronidazole, amoxicillin + clavulanate, and others.
Interventions	Group A ‐ Mechanical bowel preparation (n = 236): PEG + bisacodyl (11 hospitals) or sodium phosphate solution (2 hospitals); fluid diet on the day before surgery. Group B ‐ normal meals (n = 213).
Outcomes	Anastomotic dehiscence: Group A = 18; Group B = 14. Wound infection: Group A = 39; Group B = 36. Intraabdominal abscess: Group A = 6; Group B = 9. Mortality: Group A = 7; Group B = 9. Urinary tract infection: Group A = 34; Group B = 26. Pneumonia: Group A = 16; Group B = 20. Fascia dehiscence: Group A = 7; Group B = 2. Overall complications: Group A = 92 (39%); Group B = 83 (39%).
Notes	Diverting ileostomy: n = 48 (no stoma = 401). Stoma: Group A = 27; Group B = 21.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Low risk	A ‐ Adequate