Background Pelvic floor damage is a major clinical problem usually attributed to obstetric injury. We speculated that constipation may also be an aetiological and preventable factor resulting from repeated stress on the perineum over many years, and this study aimed to test this hypothesis. Methods A total of 600 women attending a gynaecological clinic were assessed using a structured questionnaire gathering data on pelvic floor damage, constipation and obstetric trauma. Complete data were available on 596 subjects. Key Results The prevalence of pelvic floor damage was 10% (61/596). In this group, constipation was identified in 31% (19/61) of women and obstetric trauma in 31% (19/61). In the group without pelvic floor damage, constipation was present in 16% (86/535) and obstetric trauma in 16% (83/535). In univariate analysis, pelvic floor damage was associated with age (OR: 1.05; 95% CI: 1.03-1.08; P <0.0001), constipation (OR: 2.36; 95% CI: 1.31-4.26; P <0.0001) and obstetric trauma (OR: 2.46; 95% CI: 1.37-4.45; P <0.0028). In multivariate analysis, the OR for age was 1.05 (95% CI: 1.03-1.08; P <0.0001), for constipation 2.35 (95% CI: 1.27-4.34; P <0.0001) and for obstetric trauma 1.37 (95% CI: 0.72-2.62; P = 0.3398). Conclusions & Inferences Constipation appears to be as important as obstetric trauma in the development of pelvic floor damage. Thus, a more proactive approach to recognizing and treating constipation might significantly reduce the prevalence of this distressing problem. © 2009 Blackwell Publishing Ltd.