Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Frequency of bowel movement
Systematic review	People (>90% aged >16 years) with idiopathic chronic constipation (modified Rome II criteria and negative investigations) 3 RCTs in this analysis	Failure to respond to therapy (response defined as increase to 3 or more spontaneous bowel movements [SBMs] per week from baseline [1 RCT]; 3 or more SBMs per week [1 RCT]; or 4 or more SBMs per week [1 RCT]) 151/335 (45%) with lubiprostone 184/275 (67%) with placebo	RR 0.67 95% CI 0.56 to 0.80 P <0.0001 NNT 4 95% CI 3 to 7 See Further information on studies	Small effect size	lubiprostone
RCT 4-armed trial	People, average age about 40 years, with idiopathic chronic constipation	Changes in the weekly average number of SBMs from baseline at 1 week with highest-dose lubiprostone with placebo Absolute results reported graphically	P <0.01 Results were also significant at 2 weeks (P <0.01) Post hoc analysis	Effect size not calculated	lubiprostone
RCT 4-armed trial	People, average age about 40 years, with idiopathic chronic constipation	Changes in the weekly average number of SBMs from baseline at 1 week with middle-dose lubiprostone with placebo Absolute results reported graphically	P <0.01 Results were also significant at 2 weeks (P <0.05) Post hoc analysis	Effect size not calculated	lubiprostone
RCT 4-armed trial	People, average age about 40 years, with idiopathic chronic constipation	Changes in the weekly average number of SBMs from baseline at 1 week with lowest-dose lubiprostone with placebo Absolute results reported graphically	Reported as P <0.1 Results were not significant at 2 weeks (P value not reported) Post hoc analysis		Not significant