Table 1 Summary of prospective, placebo-controlled studies of antibiotics for treating irritable bowel syndrome

Study	n	Entry criteria	Treatment	Outcome (% improved)
Pimentel 2003	43	Rome I	Neomycin	35%
	44 placebo		500 mg bid	11%
				p<0.05
Sharara 2006	63	Gas/flatulence	Rifaximin	29%
	61 placebo	59% Rome II	400 mg bid	12%
				p = 0.03
Pimentel 2006	55	Rome I	Rifaximin	36%
	56 placebo		400 mg tid	21%
				p = 0.026

bid, twice a day, tid, three times a day.