Jalihal 1990.

Methods	RCT with Cross‐over design
Participants	20 patients Gastro intestinal outpatients clinic Diagnoses on clinical grounds Mean age 38 years 20% female
Interventions	Bulking agent 4 weeks ispaghula husk 30 g/day
Outcomes	Abdominal pain, dichotomous Global assessment, dichotomous
Notes	GI Outpatients No run‐in
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Low risk	Adequate
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind, treatment was indistinguishable from the placebo
Incomplete outcome data (attrition bias) All outcomes	Low risk	No drop‐outs. Two patients were eligible but dropped out before the study.
Selective reporting (reporting bias)	Low risk	Expected outcomes were reported
Other bias	Low risk	The study appears to be free of other sources of bias