Bowel Continence Explained
Bowel continence, a skill acquired by most toddler children, is often considered essential to psychological well-being and social functioning. Patients who suffer from bowel incontinence may be reluctant to share their symptoms with anyone, including their family doctor. This fact makes accurate estimates of the prevalence of bowel incontinence in the general population rather difficult. The number of people afflicted with bowel incontinence in Europe is thought to be around 53 million.
When assessing the situation it is important to understand the mechanisms behind bowel continence. Bowel continence is maintained essentially through the action of the anal sphincters, the internal and external anal sphincters. The anal sphincters are muscles which are normally contracted at rest, a property referred to as myogenic tone, and whenever defecation is to occur, these muscles relax allowing the faeces to pass. The internal anal sphincter (IAS) is sometimes considered the key to bowel continence. The natural resting tone which prevents soiling is attributed primarily to the properties of the internal anal sphincter. When the internal anal sphincter is damaged, patients often complain of passive faecal incontinence, where the faecal soiling occurs without the patient being aware of the leak. This passive soiling occurs most readily with soft stools or small pellets of faeces. This type of soiling may occur after the bowel has been emptied, or during physical exertion.
Bowel incontinence is also a function of the integrity of the external anal sphincter. The external anal sphincter (EAS) is formed of skeletal muscles, i.e. muscles which are under voluntary control. Whenever there is an urge to defecate or pass wind, one can voluntarily contract the external anal sphincter to “hold on”. Damage involving the external anal sphincter commonly results in what is known as faecal urge incontinence, which is a condition where patients find themselves unable to suppress the urge to defecate. They complain of soiling especially in cases of diarrhoea.
It is worth noting that the external anal sphincter is part of the pelvic floor muscles, which also play an essential role in preventing bladder leaks. And because of that, in many instances, urinary incontinence may co-exist with faecal incontinence. Obstetric, or child-birth related injuries are the most common forms of damage to the pelvic floor muscles, which could result in loss of both bladder and bowel continence.
Assessment of the proper functioning of both the internal and external anal sphincters is possible through a simple procedure, which is Endorectal Ultrasound (ERUS). The Endorectal ultrasound is inserted into the rectum to allow visualization of the rectal wall and anal sphincters. Any defects or tears in the anal sphincters are detected, which allows the physician to determine whether the patient is an appropriate candidate for surgery to restore bowel continence.
Surgery is not the only option available for patients with bowel incontinence. There are many other conservative methods available, including rehabilitation and medications. After careful assessment and identification of the underlying causes, the physician will be able to decide on the action plan geared towards restoration of bowel continence.
Filed under: Bowel Incontinence