Guthrie 1993.

Methods	12‐week, single‐centre RCT with 2 parallel conditions
Participants	102 participants who had been diagnosed with IBS and had been experiencing symptoms for > 1 year, and who had been treated for a minimum of 6 months with no improvement on bulking agents, antispasmodic therapy, or both
Interventions	Intervention: dynamic psychotherapy based on the conversational model of Hobson 1985 consisting of 1 long 2‐hr session, and 6 follow‐up sessions or a control group at attended on 3 occasions (2, 4 and 8 weeks) to discuss their daily bowel habits Control: standard care All participants continued standard medical treatment in the gastroenterology clinic
Outcomes	Pre‐, post‐ 12‐week trial. BDI, Symptoms Rating Test, PAS (a modified PSE)
Notes	Same trial as Guthrie (1991) but further data analysis and later follow‐up BDI score used at end‐treatment
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: insufficient information
Allocation concealment (selection bias)	Unclear risk	Comment: insufficient information
Blinding (performance bias and detection bias) All outcomes	Low risk	Comment: self report measures (BDI) considered low risk of detection bias
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "data for drop‐outs have been included in the results that indicate the overall efficacy of treatments" Comment: similar drop‐outs between groups, data collected for all but 2 of dropouts and included in analyses
Selective reporting (reporting bias)	Unclear risk	Comment: insufficient Information to permit judgement. No published report on pre‐specified outcomes
Other bias	Unclear risk	Comment: insufficient information to permit judgement