Faecal incontinence associated with acute gastroenteritis does not indicate proctological investigations unless it becomes prolonged or recurrent.
Inquire actively about faecal incontinence in patients with anorectal problems, as incontinence is not often reported spontaneously.
Epidemiology
The prevalence of faecal incontinence in the general population is generally reported to be approximately 2-3% 1. In a Finnish population survey, up to 5% of adult subjects suffered from symptoms of faecal incontinence occurring at least twice a month 2.
The symptom is most common in the elderly but a considerable proportion of the patients are of working age.
Aetiology
Acute infectious diarrhoea
Faecal impaction (overflow incontinence)
Over-consumption of laxatives (common in the elderly)
Injuries of the anal sphincter
Operations: anal fistula, dilatation of the anus
Delivery
Pelvic fractures and other direct injuries
Rectal prolapse
Rectal intussusception
Anorectal tumours
Congenital malformations
Neurological diseases: sequelae of cerebral infarction, multiple sclerosis, tetraplegia, intervertebral disk herniation, dementia
Proctitis, colitis
Idiopathic (neurogenic)
Investigations
Ask about the duration and frequency of the symptom, consistency of leaking faeces (hard? diarrhoea?), surgery on the lower abdomen, the anal canal and the back, and, particularly, neurological diseases and drugs used by the patient (over-consumption of laxatives).
Proctological examination is the basis of diagnosis: inspection, digital rectal examination, proctoscopy and endoscopy of the bowel. These examinations are always indicated, with the exception of transient infectious diarrhoea.
Urinary incontinence developing together with faecal incontinence suggests spinal cord disease.
Inspection
A widely open anus suggests injury of the anal sphincter or rectal prolapse/intussusception.
Ask the patient to strain down as if defecating and observe the motion of the perineum. If the perineum is lowered to the level of the ischial tuberosities, the patient has a pelvic floor prolapse which is suggestive of a neurogenic damage.
Identify eventual rectal prolapse, and vaginal or uterine prolapse in female patients.
Digital rectal examination
Determine the tone of the anal sphincter, both at rest and during contraction.
Proctoscopy and sigmoidoscopy or colonoscopy
Identify tumours and inflammation.
When the patient strains down during proctoscopy, possible rectal prolapse or intussusception can be detected.
Conditions suitable for treatment by the general practitioner
Acute infectious diarrhoea
Overflow incontinence
Incontinence caused by medication
Any patient with mild or moderate incontinence that is not caused by a tumour and who has been sufficiently investigated as regards neurological or other systemic disease, is eligible for a therapeutic trial.
Total incontinence or daily soiling of the underwear, unless the cause is definitely untreatable (severe dementia or neurological disease).
Faecal incontinence associated with rectal prolapse or intussusception is corrected by surgical suspension of the rectum in 75% of the patients.
A severed sphincter muscle can be surgically corrected.
The surgical treatment options include repair of a ruptured anal sphincter, plastic corrections of pelvic floor muscles and the perineum, and substitution of the anal sphincter. In some cases a stoma is made. This allows to keep the bowel empty when sphincter function cannot be restored.
Nelson R, Norton N, Cautley E, Furner S. Community-based prevalence of anal incontinence. JAMA 1995 Aug 16;274(7):559-61. [PubMed]
Aitola P, Lehto K, Fonsell R, Huhtala H. Prevalence of faecal incontinence in adults aged 30 years or more in the general population. Colorectal Dis 2006;8 Suppl 4:F011 http://www.escp.eu.com/webfm_send/57