Bonnert 2017.

Methods	RCT. 2 arms. Assessed at pretreatment, post‐treatment, 6 months
Participants	End of treatment: N = 95, 6‐month follow‐up (tx only) N = 42 Start of treatment: N = 101 Sex: 62 F, 39 M Mean age: 15.54, SD = 1.56 (range 13‐17) Source: primary, secondary, and tertiary care clinics Diagnosis: irritable bowel syndrome Mean years of pain: 23 participants reported symptoms from 2 to 11 months, 78 reported symptoms for more than 12 months. Mean durations of symptoms reported by parents = 5.12 (SD = 4.11) years
Interventions	"Exposure‐based Internet‐CBT with therapist support" "Wait‐list control". Participants in the waiting list were asked not to initiate any psychological treatment during the waiting list period of 10 weeks
Outcomes	Primary pain outcome: Faces Pain Scale‐revised Primary disability outcome: none Primary depression outcome: none Primary anxiety outcome: Spence Children's Anxiety Scale Primary satisfaction outcome: Client Satisfaction Questionnaire Measures reported: Gastrointestinal Symptom Rating Scale‐IBS version Faces Pain Scale‐revised Pediatric Quality of Life Inventory Children's Somatization Inventory School absence IBS‐Behavioral Responses Questionnaire Visceral Sensitivity Index Perceived Stress Scale Spence Children's Anxiety Scale Client Satisfaction Questionnaire
Notes	Funding source: Jan and Dan Olsson Foundation (4‐1559/2013), the Swedish Research Council (521‐2013‐2846), the Kempe‐Carlgren Foundation, the Ruth and Richard Julin Foundation (2012Juli0048), the Majblomman Foundation, the Ishizu Matsumurais Donation, the Ihre Foundation (SLS‐331861), the Ihre fellowship in Gastroenterology, the Gadelius Foundation, the Samariten Foundation, the Värkstadsstiftelsen Foundation, the Swedish Research Council for Health, Working life and Welfare (2014‐4052), the Swedish Society of Medicine (SLS‐331681 SLS‐410501), and the Stockholm County Council (ALF). Financial support was also provided through the regional agreement on medical training and clinical research between Stockholm County Council and Karolinska Institutet (20130129). None of the funding bodies had any influence on study design, implementation, data analysis, or interpretation Declarations of interest: authors declare no conflicts of interest
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Participants were consecutively randomized to either exposure‐based Internet‐CBT or wait‐list. The randomization was conducted by an independent researcher, who received lists with anonymous study ID numbers and used a random number service (www.random.org)" Comment: probably done
Allocation concealment (selection bias)	Low risk	"The randomization was conducted by an independent researcher, who received lists with anonymous study ID numbers and used a random number service (www.random.org) to allocate participants, thus ensuring concealment of allocation." Comment: probably done
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No description found in text Comment: probably not done
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Measures completed online
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Attrition is described, however significant descriptions between completers and non‐completers were not reported
Selective reporting (reporting bias)	Low risk	Data were fully reported