Passaretti 1989a.

Methods	RCT
Participants	40 patients Out patient clinic Mean age 39 years 60% females
Interventions	Spasmolytic 4 weeks cimetropium tds 50 mg
Outcomes	Abdominal pain, continuous Global assessment, dichotomous
Notes	2 weeks run‐in without placebo
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	Double‐blind, methods not described
Incomplete outcome data (attrition bias) All outcomes	Low risk	Missing outcome data balanced in numbers across intervention groups with similar reasons for missing data across groups
Selective reporting (reporting bias)	Low risk	Expected outcomes reported
Other bias	Low risk	The study appears to be free of other sources of bias