Steinhart 1996.

Methods	A 6‐week, randomised, double‐blind trial (N = 38)
Participants	43 patients were initially randomised; 5 patients were excluded due to protocol violations Patients were diagnosed with ulcerative proctosigmoiditis and had endoscopic evidence of inflammation occurring between 5‐60 cm from the anal verge
Interventions	Nightly butyrate enema (n = 19) or placebo (saline) enema (n = 19) Maximum treatment duration was 6 weeks Concomitant oral medications were held constant Topical rectal therapies were discontinued
Outcomes	Primary outcome: clinical improvement (a decrease in UCDAI > 2 or a score < 3 at week 6) Secondary outcomes: complete response (remission or complete response, as defined by a UCDAI score < 3), UCDAI score, endoscopic mucosal appearance, histological grade, adverse events, compliance
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	Low risk	The concentration, dose and frequency of the enemas were identical
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described
Incomplete outcome data (attrition bias) All outcomes	Low risk	Drop‐outs were balanced across groups with similar reasons for withdrawal 28/38 patients completed the 6 week study (14 placebo, 14 experimental)
Selective reporting (reporting bias)	Low risk	All expected outcomes were reported
Other bias	Unclear risk	The study appears to be free of other sources of bias