Zuspan 1960.

Study characteristics
Methods	Study design: quasi‐randomised trial Trial setting: Department of Obstetrics and Gynaecology, University Hospital Cleveland, Ohio. USA Trial location: USA
Participants	244 postpartum women
Interventions	Intervention: Dioctyl‐sodium succinate (50 mg) + senna (225 mg); 1 capsule twice daily. The 1st capsule was given as soon postpartum as practical. No other laxative drugs given except enema saponis at patients’ request. Control: capsulated inert ingredients (placebo), 1 capsule twice daily. 1st dose given as soon postpartum as practical. No other laxative administered except enema saponis at patients’ request.
Outcomes	1. Number of days before 1st spontaneous bowel movement 2. Number of capsule (laxative) taken before 1st spontaneous bowel movement 3. Number of postpartum enemas given
Notes	Purdue Fredrick Co. supplied the laxative (Senokap) used for the trial Dates of study: no information supplied Funding sources: the laxative used for the trial was supplied by Purdue Fredrick Co. Declarations of interest: not declared
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	There was no information on random allocation sequence generation method (quasi‐RCT).
Allocation concealment (selection bias)	High risk	Quasi‐randomised trial
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote "All patients received double blinded capsule as soon postpartum as practical and they were intentionally not told whether the capsule was a laxative or not". No report on method used to blind both the participants and personnel
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information was given on how knowledge of allocated interventions was prevented during measurement of outcomes.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No information was provided on the flow of participants.
Selective reporting (reporting bias)	Low risk	No published protocol available, but the prespecified outcomes were addressed adequately. Prespecified outcomes 1. Number of days before 1st spontaneous bowel movement 2. Number of capsules (laxative) taken before 1st spontaneous bowel movement 3. Number of postpartum enemas given
Other bias	Unclear risk	Ethics approval not stated Purdue Fredrick Co. supplied the laxative (Senokap) used for the trial Conflict of interest was not addressed; we are not sure if there was a conflict of interest

RCT: randomised controlled trial