Study | Country, and number of centres | Setting | Criteria used to define chronic idiopathic constipation | Criteria used to define response | Number of patients (% female) | Laxative used | Duration of therapy | Methodology |
Wesselius-De Casparis 196824 | Holland and Croatia, 3 sites | Secondary and tertiary care | Need for regular laxative use | No requirement for additional laxatives during treatment period | 103 (not stated) | Lactulose 15 ml od (dose doubled if no response) | 3 weeks | Randomisation and concealment of allocation unclear, double-blind |
Baldonedo 199125 | Venezuela, 1 site | Secondary care | Compatible symptoms and negative investigations | Mean number of stools per week | 31 (93.5) | Polyethylene glycol 500 ml od | 8 days | Randomisation and concealment of allocation unclear, double-blind |
Corazziari 199626 | Italy, 6 sites | Secondary and tertiary care | Rome I criteria and negative investigations | ≥3 stools per week Mean number of stools per week | 48 (77.1) | Polyethylene glycol 17.5 g bid | 8 weeks | Randomisation and concealment of allocation stated, double-blind* |
Corazziari 200027 | Italy, 5 sites | Secondary and tertiary care | Rome criteria (iteration unspecified) and negative investigations | ≥3 stools per week without the use of rescue laxatives, and no straining, hard stools, or tenesmus Mean number of stools per week | 70 (82.9) | Polyethylene glycol 17.5 g bid | 20 weeks | Randomisation and concealment of allocation stated, double-blind* |
DiPalma 200028 | USA, 4 sites | Secondary and tertiary care | Compatible symptoms and negative investigations within the last 2 years | >3 stools per week without the use of rescue laxatives Mean number of stools per week | 151 (86.8) | Polyethylene glycol 17 g od | 2 weeks | Randomisation and concealment of allocation stated, double-blind* |
DiPalma 200729 | USA, 50 sites | Secondary and tertiary care | Rome I criteria and negative investigations | ≥3 stools per week without the use of rescue laxatives, and ≤ 1 of straining, hard stools, or tenesmus Mean number of stools per week | 304 (84.9) | Polyethylene glycol 17 g od | 6 months | Randomisation and concealment of allocation stated, double-blind* |
Kamm 201031 | UK, 27 sites | Primary care and commercial centres | Rome III | ≥3 CSBMs per week Mean number of stools per week | 368 (74.7) | Bisacodyl (Dulcolax) 10 mg od | 4 weeks | Randomisation and concealment of allocation stated, double-blind* |
Mueller-Lissner 201030 | Germany, 45 sites | Primary care | Rome III | ≥3 CSBMs per week Mean number of stools per week | 367 (77.7) | Sodium picosulfate (Dulcolax) 10 mg od | 4 weeks | Randomisation and concealment of allocation stated, double-blind |
↵* Full information not reported in published article, but obtained after correspondence with the authors.
bid, twice daily; CSBM, complete spontaneous bowel movement; od, once daily.