At the functioning level, persons with SCI/SCD are often confronted with urinary incontinence i.e. loss of bladder control, and bladder dysfunction e.g. constipation and stool retention. Given that many of the nerves that control the bowel and bladder are located in the lower spine, a SCI/SCD can directly impact, to varying degrees, a person’s ability to urinate and defecate (i.e. discharge of stool) normally.123 Additionally, persons with SCI/SCD are at increased risk of developing urinary tract infections (UTIs), bladder cancer, bladder and kidney stones and renal failure.3
Neurogenic Bowel and Bladder
The terms neurogenic bowel or neurogenic bladder refer to dysfunction in the respective organs following central or peripheral nervous system injuries. The clinical manifestation of both is largely related to the location of the lesion and the motor neurons involved.123
Box 1 | Pathophysiology of Neurogenic Bowel and Bladder
Neurogenic Bowel
The function of the bowel is regulated by the autonomic nervous system (or the automatic actions of the body), involving both the parasympathetic and the sympathetic nervous systems. While the parasympathetic nervous system increases peristalsis (i.e. the contraction of the intestinal muscles that propel contents through the digestive tract), stimulates gastrointestinal secretions, relaxes sphincters, and increases intestinal contractions, the sympathetic nervous system decreases peristalsis, limits production of secretions, tightens sphincters, and decreases intestinal contractions. While the parasympathetic actions of the gastrointestinal tract are stimulated by the pelvic nerve that has its origins in the sacral region S2-S4 of the spinal cord (bottom of the spine), sympathetic actions are stimulated by the nerve fibres that originate from the spinal cord region between the thoracic segment T5 and the lumbar segment L2 (area between the back and thigh).12
Normal bowel functioning involves a sequence of actions beginning with involuntary activities:
- Contractions of the colon moves stool through the colon to the rectum
- Enlargement of the rectum resulting from the relaxation of the internal anal sphincter muscle
- An urge to defecate then begins
- Simultaneously, a holding reflex occurs, in which an increase in muscle tone of the external anal sphincter (EAS) muscle halts the discharge of stool
and followed by voluntary actions of relaxing the EAS and contracting the anal muscles to discharge stool.12
A person with SCI/SCD may experience different impairments in bowel function depending on the level of the SCI/SCD. In SCI with a lesion above T12 (or above the waist) upper motor neuron syndrome occurs in which the EAS becomes spastic and tightens, voluntary control of the sphincter is lost but reflex activity remains. This can cause constipation and stool retention. In SCI with a lesion below T12 (or below the waist) and where lower motor neurons are affected, the EAS is deprived of nerve impulses resulting in a flaccid (or loose) EAS, and both voluntary and reflex activity are lost. This can lead to bowel incontinence, diarrhoea, as well as constipation.124
Other complications of neurogenic bowel dysfunction include ulcers, gastroesophageal reflux (return of stomach contents toward the mouth), haemorrhoids, anal lesions, nausea, appetite loss, and autonomic dysreflexia, a condition that generally occurs in SCI with lesions at or above T6 (mid-chest) manifested in high blood pressure, slow heart rate and severe headaches.12456
Neurogenic Bladder
The function of the bladder is regulated by the interaction between the parasympathetic, sympathetic and somatic (or voluntary) nervous systems that supply nerve impulses to the lower urinary tract i.e. bladder and urethra. While the parasympathetic system controls the contraction of the bladder and the release of urine from the bladder, the sympathetic system is responsible for storage of urine. The somatic nervous system, with nerves originating from the sacral region of the spinal cord, enables the voluntary regulation of the external urethral sphincter (EUS) i.e. the muscle that controls the exit of urine.137
Normally, the process of storing urine and emptying the bladder is an unconscious process. When the bladder is full, signals are sent from the mid-brain through the pelvic nerve to the bladder. The bladder contracts and the sphincter at the neck of the bladder relaxes allowing the urine to pass through the urethra. The person voluntarily relaxes the EUS for the final act of urination.37
Following a SCI a 2-12 week period of “spinal shock” occurs, during which bodily reflexes do not work at all. During this time the bladder has no contractions, and temporary inability to empty the bladder is common. After recovering from spinal shock, the person with SCI generally experiences an overactive bladder and urinary incontinence.137
Like with neurogenic bowel dysfunction, symptoms of neurogenic bladder dysfunction depend upon the location of the lesion. Persons with lesions above the sacral spinal cord region generally experience overactive contractions of the bladder along with intermittent and uncoordinated contractions of the sphincter. Persons with sacral lesions generally experience an absence of bladder contraction. The bladder fills until the sphincter is no longer able to hold up the pressure from the full bladder, and urinary incontinence occurs.37 Due to the various patterns of bladder dysfunction presented by incomplete SCI, predicting the bladder function of persons with incomplete SCI after spinal shock solely on the lesion level is not possible.7
Complications associated with bladder dysfunction include autonomic dysreflexia, UTIs, bladder and kidney stones, swelling of a kidney due to the inability to drain urine from the kidney into the bladder, backward flow of urine from the bladder to the kidneys, and renal failure.13
Clinical Interventions to Address Neurogenic Bladder
Treatment for neurogenic bladder aims to normalise bladder functions, prevent secondary conditions, and achieve and maintain urinary continence.
During the acute phase following SCI or onset of bladder dysfunction in SCD, the use of indwelling catheters (or catheters implanted in the body) is universally expected. However, due to increased risk of UTIs, indwelling catheters should be removed as soon as the person is stabilised.7 In addition to indwelling catheters, there are other catheterisation methods. The method of catheterisation should be decided on an individual basis and in consideration of the person's lesion level, sex, functioning status, finances, preferences and desire for sexual intercourse.1 For example, intermittent catheterisation, i.e. insertion and removal of a catheter several times a day, may be the ideal option for persons who are able to self-catheterise. For men experiencing an overactive bladder, a condom catheter combined with intermittent catheterisation may be an option for emptying the bladder.1347
In addition to catheterisation, pharmacological treatment is also an option, for example to suppress uncontrolled bladder contractions, increase bladder capacity or firming up the sphincter. A disadvantage of treating with medication is the appearance of possible side effects, such as dry mouth, visual disturbances and constipation.137
Surgical interventions, such as placement of urethral stents or augmentation cystoplasty, can also be performed to address bladder dysfunction. Urethral stents can be placed in the urethra to open up the blockage of urine caused by a dysfunctioning sphincter. Augmentation cystoplasty is the enlargement of the bladder to increase storage capacity of the bladder.137
Clinical Interventions to Address Neurogenic Bowel
Treating bowel dysfunction requires careful management to ensure bowel discharge occurs in a timely and predicted manner, to maintain continence, and to avoid constipation.1268 For this purpose, it is essential that the pattern of bowel discharge is charted. A clinical examination can provide information about sphincter tone, presence of haemorrhoids and cuts, and voluntary control of muscle contractions, among other things.18
Before a bowel management programme is established, a comprehensive assessment of the following should also be conducted:12
- Gastrointestinal history (e.g. presence of inflammatory bowel disease) and history of other health conditions (e.g. diabetes) including medications that may affect bowel management choice
- Dietary habits and preference
- Activity level and lifestyle
- School and work situation
- Ability to perform bowel management activities independently
- Mobility-related aspects of functioning e.g. muscle strength of upper and lower extremities, sitting balance, ability to transfer
- Length of arms, legs, trunk
- Body weight
There are various options of treatment and techniques that can be applied within a bowel management programme. For example, manual evacuation of stool and colon massages may be options for addressing the absence of or insufficient bladder contractions. Medications like stool softeners and bulking agents can be employed to ensure adequate stool consistency and facilitate stool evacuation. Also useful in stool evacuation is finger stimulation of the rectal wall and suppositories. Enemas are used only when medication and suppositories have not been successful in releasing stool blockage in the colon, and surgical interventions are only performed if the conventional approaches have proven unsuccessful. Although no established guidelines are available, adequate fluid intake and a balanced diet are viewed as contributors to successful bowel management.12468
Impact of Neurogenic Bowel and Bladder on Daily Life
The treatment and management of bowel and bladder dysfunction may impact various aspects of daily life and ultimately quality of life.1236789 Bowel and bladder management dictates a person's daily routine – the where and when daily activities are performed. Specific management methods have to be performed during certain times of the day or frequently over the course of the day. It can be quite time-consuming. Moreover, the fear of bowel or bladder accidents and not being able to readily access toilet facilities may discourage the persons with SCI/SCD from going to certain places or participating in social activities – consequently leading to social isolation.2569
Persons who experience bowel and bladder dysfunction often sub-consciously develop behaviours that help them cope with their situation, but may eventually have a negative impact on daily life. For example, persons with bladder dysfunction may drink less to reduce filling the bladder. However, insufficient fluid intake may cause dehydration, constipation or other health problems.9
""From a rehabilitation perspective, the overarching goal is to achieve optimal functioning of bowel and bladder functioning.""
From a rehabilitation perspective, the overarching goal is to achieve optimal functioning of bowel and bladder functioning. Rehabilitation should be individualised, integrative and multidisciplinary, involving the person with SCI/SCD in the rehabilitation process. Self-management of bowel and bladder is one of the most important issues that are addressed in rehabilitation.6710
This case study illustrates the challenges faced by Marco, a person with the SCD Behçet's syndrome, in managing bladder and bowel dysfunction. The case study also highlights the importance of developing an appropriate, person-focused programme for bowel and bladder management as part of the rehabilitation process.