Sutherland 1987b.

Methods	6‐week, randomised, double‐blind placebo‐controlled design (N = 59)
Participants	Patients were > 18 years who had UC involving 5‐50 cm of colon continuously from the anus, confirmed by sigmoidoscopy with biopsies taken from an area of active disease Patients had to have a minimum score of 3 on a 12‐point DAI
Interventions	Group 1: 4 g 5‐ASA enema (60 mL) (n = 29) Group 2: placebo enema (n = 30) Patients were instructed to use one enema daily at bedtime
Outcomes	Primary outcome: physician's global assessment of the patient at the end of the study period, mean DAI
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random numbers table
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind medication was prepackaged to ensure that an equal and random assignment within each centre occurred
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Drop‐outs balanced across groups with similar reasons for withdrawal There were 12 dropouts (five in the active and seven in the placebo group) during the study because of insufficient efficacy
Selective reporting (reporting bias)	Unclear risk	All expected outcomes were reported
Other bias	Unclear risk	The study appears to be free of other sources of bias