title: Internal anal sphincter dysfunction in neurogenic faecal incontinence.
abstract: Forty-eight patients of median age 57 years with neurogenic faecal incontinence and 44 normal subjects of median age 51 years underwent fine-wire anal sphincter electromyography and anal manometry. The median (interquartile range (i.q.r.)) internal anal sphincter (IAS) electromyogram frequency was 0.26 (0.21-0.32) Hz for patients with faecal incontinence and 0.44 (0.31-0.55) Hz for controls (P < 0.01). The median (i.q.r.) ambulatory resting pressure was 48 (34-68) cmH2O for patients and 86 (72-102) cmH2O for controls (P < 0.01) and median (i.q.r.) frequency of transient IAS relaxations 9 (7-12) and 4 (3-7) per h respectively (P < 0.05). Mid-anal pressure fell to a greater extent in patients with incontinence during these episodes of transient IAS relaxation. Rectal pressure during such relaxation did not exceed mid-anal canal pressure in controls; for the patient group, rectal pressure increased during relaxation and exceeded mid-anal canal pressure in 36 cases. Frequent abnormal episodes of IAS relaxation may cause occult faecal leakage in patients with neurogenic faecal incontinence.
authors.affiliation: Department of Surgery, Royal Infirmary, Edinburgh, UK.
authors.forename: R
authors.initials: R
authors.lastname: Farouk
authors.forename: G S
authors.initials: GS
authors.lastname: Duthie
authors.forename: A
authors.initials: A
authors.lastname: Pryde
authors.forename: A B
authors.initials: AB
authors.lastname: McGregor
authors.forename: D C
authors.initials: DC
authors.lastname: Bartolo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001003:Anal Canal / Q000503:physiopathology*; D004576:Electromyography / Q000379:methods; D005242:Fecal Incontinence / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009126:Muscle Relaxation; D011312:Pressure