Hence, a detailed obstetric history including number of vaginal deliveries, use of forceps, tears, and
episiotomy is important. Sphincter disruption, most
commonly after surgery for hemorrhoid or anal fissure, can result in incontinence. Likewise, reduced
rectal compliance causes urgency and fecal incontinence. Impaired rectal sensation results in the
accumulation of stool and overflow. Patients rarely
have a single cause, with 80% having more than
one factor that leads to incontinence.29
Clinically, fecal incontinence can be classified into
3 categories. Urge incontinence is characterized by
the inability to control stool discharge despite active
attempts to retain contents. These patients often have
disruption or injury to the external anal sphincter.
Fecal seepage is the involuntary discharge of less
than 2 tablespoons of stool matter without awareness. Seepage can result from impaired rectal evacuation and dyssynergia. Often patients with seepage
complain of incomplete evacuation. Passive incontinence refers to the involuntary discharge of stool
contents without awareness. These patients often
have underlying neuropathy and sphincter weakness.30,31
• What is the approach to evaluation and diag-
Figure 4. Anal endosonography image of a large defect in the
external anal sphincter (EAS) between 11 and 1 o’clock position.
There is also scarring in the EAS. The internal anal sphincter (IAS),
the dark halo ring, is mostly intact.
Figure 3. Defecographic changes (A) at rest and (B) during attempted defecation. Panel A shows a resting anorectal angle that
is slightly larger than normal and an anterior rectocele. Panel B
shows rectal prolapse.