Loss of control of wind or
faeces is a distressing symptom that affects one in 10
middle aged people. Sufferers lose self esteem, have a
reduced quality of life and only one third of these
people actively seek medical advice. Faecal incontinence
in the elderly is a major cause of admission to
residential care and in this setting is often
accompanied by urinary incontinence.
Central control
The central factors that are important are the requisite
intellect to recognise anorectal signals, intact
functioning central pathways and the necessary mobility
to get to the toilet. People with intellectual
impairment or significant neurological disorders such as
Parkinson's disease or spinal cord degeneration have a
high incidence of bladder and bowel incontinence.
Patients confined to wheelchairs or walkers or those who
have difficulty bending the hips to sit comfortably can
have normal awareness but may have difficulty toileting
in time to avoid accidents.
Local control
Local rectal factors that are important are
- intact anal sphincters
- a functioning puborectalis muscle to pull the rectal
angle forward
- the presence of soft tissue anal cushions to bulk up
the exit
- a healthy rectal wall with intact sensation which
informs the individual of rectal content
and fullness.
 The
Anal Sphincters
The anal sphincters are the muscles that close off the
lower end of the bowel. These two muscles wrap in an
inner (Internal Anal Sphincter) and outer (External Anal
Sphincter) circle around the anal outlet.
The
puborectalis muscle
is continuously tensioned and acts to pull the lower
part of the rectum forward, closing off the exit angle.
When defecation is planned the muscle relaxes and the
anorectal angle widens. Any damage to this muscle or its
innervation will disrupt this sequence. |
