Prantera 2012.

Methods	Randomized, double blind, placebo controlled Intention to treat not performed Twenty‐four week trial
Participants	Patients aged 18‐75, active ileal or colonic CD (CDAI 220‐400) (N = 402)
Interventions	Randomized to oral rifaximin 400 mg BID (n = 104), oral rifaximin 800 mg BID (n = 98), oral rifaximin 1200 mg BID (n = 99) or oral placebo (n = 101)
Outcomes	Primary outcome: Clinical remission (CDAI < 150) at 12 weeks Secondary outcomes: Number of patients who achieved clinical response at week 12 (reduction in CDAI score of 100 points), number of patients who maintained clinical remission at week 14 and 24 and number of patients with treatment failure (failure to achieve loss of at least 70 in CDAI score after 1 month, or an increase in CDAI score of >100 points from the baseline)
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computerized randomisation procedure
Allocation concealment (selection bias)	Low risk	Centralized randomization using an Interactive Voice Response System
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Questionaires used to collect outcomes
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	High rate of withdrawal from the study in each treatment group. (rifaximin 400 mg BID (41/106), rifaximin 800 mg BID (33/99), rifaximin 1200 mg BID (41/103) or placebo (43/102)
Selective reporting (reporting bias)	Low risk	All expected outcomes were reported
Other bias	Low risk	No other apparent sources of bias