Most people don't have a soiling accident or faecal leakage unless they have a severe bout of diarrhoea. When FI recurs or is chronic, you may have sporadic or regular accidents.
The associated symptoms may vary from being unable to hold in wind (gas), silently leaking faeces during exertion or daily activities or not being able to reach the toilet in time.
Episodes of FI can occur every day, week or month, and stools may either be watery or solid.
There are two terms linked to FI, namely:
- Urge bowel incontinence: a sudden urge to have a bowel movement but not being able to reach the toilet in time.
- Passive soiling: lack of feeling to indicate a pending bowel movement.
Other signs – such as abdominal pain/cramping, constipation, diarrhoea, bloating, passing wind (flatulence), urinary incontinence and annual irritation – may accompany FI.
Normal bowel control relies on several factors such as the proper functioning of the pelvic muscles, the nervous system (spinal cord and brain), lower section of the large intestine (the rectum) and muscles surrounding the anus (sphincter muscles). If any of these areas are injured, it can cause bowel or faecal incontinence.
Here are seven of the most common causes of bowel incontinence:1. Muscle damage
If there's injury to the muscles at the end of the rectum (anal sphincter), it may be more difficult to hold stool back effectively. Sphincter muscles can be damaged by constipation, haemorrhoids (piles) and childbirth, especially if labour involves an episiotomy or forceps delivery.2. Nerve damage
If the nerves that control sphincter movement are damaged, the sphincter muscles will not close properly. When this happens, you'll not feel the urge to go to the bathroom. Some causes of nerve damage include childbirth trauma, frequent constipation, spinal cord injury, stroke and illnesses such as multiple sclerosis and diabetes.3. Diarrhoea
Loose or watery stools associated with diarrhoea can cause or worsen faecal incontinence. Having loose stools can cause such a sudden urge to have a bowel movement that you're unable to get to the bathroom in time.
Chronic constipation may cause nerve damage and also lead to an accumulation of dry, solid stool in the rectum (impacted stool) that's too bulky for normal passage. This may cause the intestinal and rectal muscles to stretch and eventually weaken, allowing watery stool located higher in the digestive tract to move around the impacted stool and leak out.
Because certain illnesses such as ulcerative colitis, irritable bowel syndrome (IBS) and Crohn’s disease can also cause chronic or recurring diarrhoea, it’s really important to consult your doctor if you have FI.
External haemorrhoids (enlarged veins in the anus or rectum) can obstruct the sphincter so it's unable to close completely, therefore allowing an involuntary leakage of mucus and loose stool.6. Medications
Several medications can also cause or worsen FI. These include broad-spectrum antibiotics, beta blockers, laxatives and antidepressants (especially tricyclics and SSRIs – selective serotonin reuptake inhibitors).
7. Pelvic-floor dysfunction
During childbirth, women can sustain injuries to nerves and muscles in the pelvis, but symptoms of pelvic floor dysfunction may only occur years or even decades later. These injuries include weakened pelvic muscles used during bowel movements, rectocele (when the rectum protrudes through the vagina because the thin muscles between the two become weak) and rectal prolapse (when the rectum drops down into the anus).