Bretagnol 2010.

Methods	Randomisation was performed centrally via an interactive voice randomisation system. Single‐blinded: the surgeon was blinded to the randomisation process and the preparation status of all patients. Withdrawal/dropout:7 patients were excluded (5 missing consent form, 1 refusal of surgical treatment, 1 loss of follow‐up). Follow‐up: 30 days postoperative.
Participants	Inclusion criteria: all the patients aged 18 years or old with rectal cancer who underwent laparoscopic or open elective rectal resection with mesorectal excision and sphincter preservation. Exclusion criteria: very low tumours (abdominal perineal excision): metastasis in the liver or lungs; T4 rectal cancer; synchronous adenocarcinoma; and/or gastrointestinal disease, refusing extensive colonic surgery. Diseases: rectal cancer. Number of participants: 178 (102 male; 76 female). Age: 54 ‐ 71 years. Location of study: 8 french hospitals (Paris (2 hospitals), Bordeaux, Montpellier, Marseilles, Toulouse, Boulogne Billancourt, Clermont‐Ferrand). Antibiotics: 500 mg of metronidazole + 1 g of ceftriaxone at anaesthetic induction and were continued every 2 hours during the surgical procedure.
Interventions	Group A ‐ MBP (n = 89): oral laxatives and retrograde enemas ‐ senna solution. After the preparation diet was confined to clear fluids. Group B ‐ no MBP (n = 89): no preoperative dietary restrictions.
Outcomes	Anastomotic leakage: Group A = 8, Group B ‐ 17 ‐ Asymptomatic anastomotic leakage: Group A = 2, Group B = 3; ‐ Clinical anastomotic leakage: Group A = 6, Group B = 14. Wound abscess: Group A = 3, Group B = 1. Pelvic abscess: Group A = 1, Group B = 7. Peritonitis: Group A = 2, Group B = 6. Reoperation: Group A = 12, Group B = 5. Infectious abdominal complications: Group A = 15, Group B = 34. Infectious extra abdominal complications: Group A = 1, Group B = 1. Non infectious abdominal complications: Group A = 7, Group B = 14. Non infectious extra abdominal complications: Group A = 5, Group B = 1. Necessity to rectal stump washout intra operatively for pool preparation: Group A = 43, Group B = 47. Intraoperative faecal spillage: Group A = 2, Group B = 7.
Notes	A multicenter study: 8 participating national (France) hospitals. Included patients with preoperative radiotherapy and chemiotherapy. Intention‐to‐treat analysis was performed. The sample size was calculated (n = 90 participants, in each group). Temporaly ileostomy: Group A = 71, Group B = 74.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Low risk	A ‐ Adequate