Tapete 2019.

Study characteristics
Methods	RCT, cross‐over Setting: NS, Italy Study period: NR The study presents results for the IBD cohort as a whole, does not separate between CD and UC. Where separate data do exist they are presented below.
Participants	Inclusion criteria: UC or CD with normal inflammatory parameters (CRP, white blood cells) and no clinical activity (CDAI < 150 for CD and a full Mayo < 2 for UC) but with residual abdominal symptoms (abdominal pain, diarrhoea, bloating) Exclusion criteria: patients with abdominal abscess, fistula, intestinal active bleeding, or extra‐intestinal manifestations Age (mean ± SD): total cohort: 43.9 (17) years total Sex (M/F): total cohort: 28/22 total Site of disease: NS Use of concurrent medication: All participants were being treated with intravenous biologic therapy (infliximab or vedolizumab). Disease activity: inactive Disease duration: NS Number randomised: NS per IG/CG, 50 in total (CD: 25, UC: 25) Number reaching end of study: NS per IG/CG, 47 in total Number analysed: NS per IG/CG, 47 total Postrandomisation exclusion: 3
Interventions	IG: low FODMAP diet CG: high FODMAP/normal diet
Outcomes	Length of intervention: 8 weeks cross‐over (4 weeks per arm) Primary outcomes: Abdominal pain intensity was measured on a 0‐to‐10‐centimetre VAS at the beginning, at 4 weeks (end of first cross‐over arm), and at 8 weeks (end of second cross‐over arm); it was unclear if this measured pain frequency or intensity or what range was used. Secondary outcomes: None reported
Notes	Funding source: NS Conflict of interest: NS Author contact details: g.tapete@studenti.unipi.it
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	NS. We contacted the author but received no response.
Allocation concealment (selection bias)	Unclear risk	NS. We contacted the author but received no response.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not possible for this type of intervention
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	NS. We contacted the author but received no response.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Cohort presented as a whole, more information is needed. We contacted the author but received no response.
Selective reporting (reporting bias)	Unclear risk	The outcomes mentioned in methods are reported in the results, but there are no pre‐cross‐over data. We contacted the author for this information but received no response.
Other bias	Unclear risk	There is a difference in baseline pain levels, and conflicts of interest are not clear. We contacted the author but received no response.