Relationship of symptoms in faecal incontinence to specific sphincter abnormalities

We aimed to determine if the type of clinical presentation in patients with faecal incontinence correlated with the underlying sphincter pathology. One hundred fifty one consecutive patients (129 female) with faecal incontinence were classified as having either passive (faecal incontinence without the patient's knowledge) or urge incontinence (incontinence occurring with the patient's awareness, against their will because of lack of voluntary control), and were investigated by routine anorectal physiological testing and anal endosonography. Sixty six patients had passive incontinence (PI) only, 42 patients had urge incontinence (UI) only, 38 patients had combined passive and urge incontinence, and 5 patients had soiling after defaecation only. Patients with PI alone (n = 66) were significantly older than those with UI alone (PI vs UI, 60 vs 42 yr, p < 0.001), had a lower maximum resting anal pressure (51 vs 64 cm H2O, means, p = 0.02) and had a significantly (p < 0.001) greater prevalence of internal anal sphincter (IAS) defects. Patients with UI alone (n = 42) had a significantly lower maximum voluntary contraction pressure (PI v UI, 72 v 42 cm H2O, p < 0.001), and a significantly (p < 0.001) greater prevalence of external anal sphincter (EAS) defects. The clinical classification of faecal incontinence into passive and urge incontinence relates to specific patterns of abnormality of the internal and external anal sphincters.