CONCLUSION
After primary repair of major OASIS, patients are less likely to retain perfect continence compared to control groups. Ultrasonographic mostly partial sphincter defects were detected in 37% of patients on follow up, but this did not correlate to a clinical difference in faecal incontinence scores. Faecal incontinence was significantly worsened by the presence of IBS, or the inability to defer defaecation for 15 minutes. Women who did not have IBS had similar or minor incontinence scores across the study groups of major OASIS repair, primigravid or post-caesarean section.
We propose that the presence of IBS interacts with the complex neuro-physiological coordination required for continence, which may be exacerbated by Grade III/IV perineal trauma. Screening for presence of IBS is therefore a useful tool to prognosticate the risk of faecal incontinence after major OASIS, but also to assess future faecal incontinence risk, if patients are known to be at high risk for OASIS, in order to advise on optimal birthing options.