Shelton 1980.

Study characteristics
Methods	Study design: randomised controlled trial Trial setting: multi‐centre Trial location: Department of Obstetrics and Gynaecology, University of Cape Town, Groote Schuur Hospital, and Peninsula Maternity Hospitals, Cape Town, South Africa
Participants	Participants: 511 normal postpartum women with vaginal delivery White postpartum women: 267 (from GrooteSchuur Hospital) Coloured postpartum women: 204 (Peninsula Maternity Hospital) Black postpartum women: 40 Exclusion criteria: women delivered by caesarean section or complicated by 3rd degree perineal tear
Interventions	Intervention: active senna tablets ‐ 2 tablets were given in the morning and 2 tablets in the evening immediately after delivery, and 2 tablets twice daily until bowel action occurred or end of regimen (16 tablets used up) Control: placebo (powdered corn flakes and dried grass)
Outcomes	Primary outcomes 1. Initial spontaneous bowel movement within the first 24 hours of delivery 2. Initial spontaneous bowel movement within 48 hours of delivery 3. First bowel movement on the third day of delivery 4. Time of dosage 5. Time and nature of bowel action Infant side effects 1. Loose stools or diarrhoea 2. Number, colour, and nature of stools for duration of trial 3. Proportion of babies with normal stools 4. Mode of feeding Secondary outcomes 1. Enema during labour and state of perineum following delivery 2. Maternal side effects: e.g. abdominal colic pains 3. Mode of delivery
Notes	Sponsor: the drugs were supplied by Reckitt & Colman, and statistical evaluation provided by them Ethics approval: not stated Decaration of interest: not disclosed Dates of study: date of the study was not provided by the authors Funding sources: drugs used in the trial and the analysis was done by Reckitt & Colman Company Declarations of interest: not disclosed
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote ''Trial preparation was administered according to a strict double ‐ blind random selection procedure". Author did not provide sufficient information on how randomisation was done.
Allocation concealment (selection bias)	Unclear risk	Quote ''tablets (active and placebo) were identical in all respects and patient only received drugs from a numbered bottle allocated to her''. The authors did not provide sufficient information to enable a clear judgement.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote "Treatment assignment was masked from all study personnel and participants for the duration of the study". Information on methods used to mask the colour, shape, and size was not supplied.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote "Statistical analyst had no knowledge of which patients received active treatment or placebo". The code was only broken at the final stage of analysis.
Incomplete outcome data (attrition bias) All outcomes	High risk	The results of 40 participants were not included because the results showed minimal differences.
Selective reporting (reporting bias)	Low risk	All the prespecified outcomes in the method section were addressed adequately.
Other bias	High risk	Sponsor: the drugs used were supplied by Reckitt & Colman and statistical evaluation provided by them Ethics approval: not stated Declaration of interest: not disclosed