Chiarioni 2006.
| Methods | Study design: randomised controlled trial Total study duration: 12 months for both groups, 24 months for biofeedback group only |
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| Participants | 109 patients with severe constipation (Rome II criteria) for > 12 months, unresponsive to standard treatment or 30 day trial of fibre All with paradoxical contraction or non‐relaxing pelvic floor on EMG and inability to defecate 50 mL water‐filled balloon Excluded patients with slow transit Biofeedback n = 54 (3 male, 51 female) (Age ‐ mean 33.3 years (SE +/‐ 1.5 years) Controls n = 55 (2 male, 54 female) (Age ‐ mean 35.1 years (SE +/‐ 1.4 years) The authors reported groups to be similar at baseline, but no statistical analysis of comparability was reported |
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| Interventions |
Intervention group: Biofeedback: 5 weekly 30 minute training sessions EMG biofeedback with contraction and relaxation of pelvic floor displayed on monitor Practice defecation of simulated stool (50 mL water‐filled balloon) while traction applied Comparison group: Laxatives (polyethylene glycol [PEG] 14.6 g/day) plus education Five 30 minute counselling sessions: avoiding unnecessary straining, defecation posture, routine, physiology of constipation, adverse effects of PEG discussed |
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| Outcomes | Patient response to the question "how would you grade your symptom improvement: worse (0), no improvement (1), mild (2), fair (3) or major improvement (4)" (primary outcome) Bowel diary of stool frequency, laxative use (other than PEG), straining, sense of incomplete evacuation, feeling of blocked defecation (kept for 30 days prior to follow‐up visits following telephone reminder) Anorectal manometry (anal canal pressure) Surface intra‐anal EMG to measure responses to attempted defecation Ability to defecate a 50 ml water‐filled balloon (simulated stool) |
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| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Shuffled sealed opaque envelopes |
| Allocation concealment (selection bias) | Low risk | Adequate concealment: sealed opaque envelopes |
| Blinding (performance bias and detection bias) All outcomes | High risk | Not blinded |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Intent‐to‐treat analysis |
| Selective reporting (reporting bias) | Unclear risk | Not registered on a clinical trials registry |
| Other bias | Low risk | The study appears to be free of other sources of bias |