Bowel management, particularly addressing challenges like constipation and incontinence, is one of the most important considerations after a spinal cord injury (SCI). The primary and secondary consequences of bowel problems can be profound and have a severe impact on physical and mental health.
How can a back injury affect the bowels?
Injury to the spinal cord can profoundly affect all nerve function between the brain and nerves below the point of injury. There is loss of control and sensation, meaning that the injured person has no voluntary control over movement, and also loss of some of the intrinsic nervous system activity of the bowels. Losing sensation also means loss of that feeling of pressure in the bowels, which is what helps us know when to go to the toilet; knowing when to perform bowel care is a large part of managing continence for people with or without an SCI. A spinal cord injury also has an intrinsic effect on muscle and anal tone.
The point at which the spinal cord is affected has a significant impact on the nature and severity of the impact on the bowel. The higher the injury, the more impact on physical function, movement, and sensation. Aside from SCI, acute neurological events or chronic neurodegenerative conditions can result in similar bowel management challenges.
The completeness of the spinal cord injury also affects the impact of the injury on the bowel. The nerves which form a feedback loop conveying sensation and impulses for movement between the brain and the bowel, as well as some reflexive action, can be severed or damaged in a way that means that there is no control beyond that point. The damage can be partial, affecting only a portion of the bundle of nerves which comprise the spinal cord, and so some sensation, control, or tone may be retained.
Bowel problems after a spinal cord injury
There are three main contributing factors to bowel management difficulties after a spinal cord injury:
- An SCI damages our ability to sense our need to go to the toilet, meaning that we can become incontinent, passing stool before we’re prepared. An SCI can also affect our ability to control the complex voluntary mechanisms controlling bowel movements. We need intact spinal cord nerves to allow us to tense and relax our abdominal muscles, to deliberately increase muscular pressure within the abdomen, to relax the anal sphincter and to push stool out.
- An SCI that affects our mobility and motor control can make it harder to manage the physical practicalities of managing continence, including simply getting to the toilet or managing continence care. The extent of effect of the SCI might mean that the right management techniques are different from person to person depending on their levels of physical mobility and independence as well as the type of care input they have from others. Someone with intact movement and sensation in their upper body may be able to independently manage complex bowel management after a spinal cord injury, whereas someone with a high spinal cord injury affecting movement will need a different management plan with more input from carers.
- The involuntary side of the digestive process is also affected by spinal cord injury. This affects peristalsis, the movement which conveys matter through the digestive system. This affects the speed of the bowel – the rate at which the contents of the digestive system move from one end to the other. It also affects every reflex part of the process, which can include aspects like the reflexive opening – or tightening – of the anal sphincter after different forms of stimulation. The level of the SCI affects the nature of the bowel dysfunction, and a dysfunctional bowel caused by damage or disease affecting the nerves is known as a neurogenic bowel.
The Neurogenic Bowel
The area of impact of spinal cord injury affects the type of bowel dysfunction a person experiences.[i] Neurogenic bowel can also be caused by other conditions which affect the nerves of the bowel, including multiple sclerosis and stroke.
Neurogenic bowel can be grouped into two broad categories – upper motor neurone bowel and lower motor neurone bowel.[ii]
Upper motor neurone bowel syndrome, or hyper-reflexive bowel, is caused by injury above the conus medullaris – it is characterised by increased tone to the walls of the bowel and anus. Gut motility is reasonable but without voluntary control of a highly toned anal sphincter, bowel evacuation can be a challenge, and upper motor neurone bowel is associated with faecal retention and constipation. People with upper motor neurone bowel can have good results from bowel evacuation techniques which employ stimulation to promote reflex opening of the anal sphincter.
Lower motor neurone bowel, or a reflexive bowel, results from injury at the conus medullaris and/or cauda equina. People with lower motor neurone bowel have disruption to the peristaltic action of the gut triggered by higher spinal cord activity, and so gut motility is poor and stool passage time is slow, meaning constipation can be a significant problem. Lower motor neurone bowel also results in an atonic, flaccid anal sphincter and so incontinence is more likely and more difficult to manage.
The level of higher spinal injuries has an impact on a person’s voluntary bowel motility, as reduced physical movement and an inability to deliberately increase intraabdominal pressures through diaphragm control, Valsalva-type manoeuvres, or positional changes create more challenges.
Complications of bowel problems after a spinal cord injury
Continence requires careful management for people with injury to the spinal cord, and the repercussions of poor bowel management can be profound.
- Severe constipation – a build-up of hard stool in the bowel can cause serious problems without effective intervention, leading to faecal impaction, bowel perforation, and potentially serious illness.
- Damage to skin – incontinence is a huge risk factor for damage to the skin and underlying tissues, causing moisture lesions and contributing to pressure damage, fungal infections and bacterial skin infections.
- Autonomic dysreflexia – in people with cervical or high thoracic spine injuries, autonomic dysreflexia is a potentially severe complication of bodily stress which can result from various problems including constipation or tissue damage.[iii]
- Impact on daily life – if constipation, incontinence, or a lengthy and complex bowel management regime are a problem, that can have a significant impact on quality of life and a person’s ability to continue any of their usual activities. Social and family life, work and mental and physical health can suffer.
Some of the interventions used for bowel management after nervous system damage can carry their own risks as well as benefits; some of the ‘last resort’ type treatments can include surgical interventions.
Managing bowel problems after a spinal injury
Specialist care teams will always recommend the safest, least invasive methods of bowel management first, but it can take some trial and error to find an effective and acceptable method for an individual. Managing constipation and continence after SCI requires a two-pronged approach – firstly, to ensure that stool is moving through the bowel at a reasonable rate to avoid constipation, and secondly to enable effective and safe emptying of stool from the bowel.
The first – maintaining healthy bowel motility – can often be effectively managed with a healthy diet and some oral medications including stool softeners and various forms of laxative. Other non-invasive techniques like abdominal massage and positional changes can help stool propulsion.
Evacuating the bowel can be more difficult at times, as it’s important to find the right balance between constipation and the possibility of incontinence, and this depends largely on the level and completeness of the injury, or the severity of other conditions causing spinal cord damage. People with reflexive bowel emptying may always require some incontinence pads and other products, and to plan for the possibility of incontinence, but a good bowel care routine can make a huge difference. Planning bowel evacuation procedures to follow patterns of peristalsis and likely timing of the need to remove stool from the rectum can help prevent accidents. Bowel management for people with spinal injuries can involve one or more of the following[iv]:
- Diet and adequate fluid intake – a healthy diet can have a significant impact on gut motility and stool volume. For people with neurogenic bowel, a healthy diet and adequate fluid intake alone will not be enough to ensure effective bowel emptying, but can help reduce the risk of constipation and make management a little easier.
- Abdominal massage – this can be effective in supporting passage of stool through the gut and raising the pressure within the abdomen to improve expulsion of stool.[v]
- Positioning – just the pressure of stool in the rectum can trigger anal opening for some people, and so sitting on a toilet, upright and with hips and knees bent can help move stool towards, or sometimes through, the anus.
- Digital stimulation – using a gloved, lubricated finger inserted a few centimetres into the anus, then swirled around for around 30 seconds can stimulate reflex anal relaxation and result in a bowel movement. However, this reflex is not present in people with lower motor neurone bowel.
- Manual evacuation – a gloved, lubricated finger can be inserted into the anus to manually remove stool using a scooping motion.
- Suppositories – there are various types of suppository, which work to soften the stool or stimulate the bowel, with varying efficacy. Glycerin suppositories work by lubricating the rectum and anus and softening the stool, so can be useful for evacuating hardened stool in the rectum. Bisacodyl suppositories work by increasing bowel contractions approximately half an hour after insertion, but are associated with more risk of incontinence as their duration of action is not entirely predictable.
- Enemas – another way of delivering small amounts of stimulant in liquid form into the rectum, enemas can have good results for managing bowel evacuation. Larger volume enemas can be effective in some circumstances but carry more risk of bowel damage, poor retention, and, occasionally, autonomic dysreflexia.
- Trans-anal bowel irrigation – the introduction of a set volume of warm water through a balloon-cuffed rectal catheter increases the volume and fluidity of bowel contents, literally washing out the bowel.
If severe constipation is still a problem despite trials of simple and minimally invasive methods of management, some surgical interventions may be considered. These can include implanted sacral nerve root stimulation devices or a MACE – an irrigation tube implanted to flush the large bowel from the appendix.[vi] A colostomy or ileostomy are sometimes considered a last resort, but have had good results in improving quality of life for people with spinal cord injuries.[vii]
Care and support
Management of continence and constipation is one of the most important considerations after a spinal cord injury and can have a profound impact on physical and mental health and quality of life. People with spinal cord injuries who retain good use of their arms and hands may be able to perform bowel evacuation procedures independently, whereas others will need support from carers. An effective care package is one designed to work around the individual, actually enabling supported independence and covering any self-care deficits to enhance quality of life.
Bowel habits are traditionally a sensitive, even taboo subject so it’s very natural for many people to feel shy or embarrassed about having new bowel care needs and incontinence. Support groups, acceptance and openness, disability activists and social media personalities with SCI have helped make this an acceptable topic for frank discussion. The impact of continued constipation, incontinence, and the other potential problems associated with bowel dysfunction cannot be understated. Quality of life and mental health are paramount after a spinal cord injury, and poor continence management is associated with poor quality of life and mental health outcomes.[viii]
Bowel care needs a holistic and person-centred approach. The method needs to be effective, preventing constipation and incontinence; practical and practicable in terms of care input and availability of an appropriate setting and equipment; and acceptable to the individual. Effective care includes monitoring, essential for early identification and management of emerging problems. Abdominal distention, autonomic dysreflexia, new patterns of incontinence and constipation can all indicate problems that need to be addressed.
_____________________________________________________________________________________________
[i] Hughes M. (2014). Bowel management in spinal cord injury patients. Clinics in colon and rectal surgery, 27(3), 113–115. https://doi.org/10.1055/s-0034-1383904
[ii] Krassioukov, A., Eng, J. J., Claxton, G., Sakakibara, B. M., & Shum, S. (2010). Neurogenic bowel management after spinal cord injury: a systematic review of the evidence. Spinal cord, 48(10), 718-733.
[iii] Cragg, J., & Krassioukov, A. (2012). Autonomic dysreflexia. Cmaj, 184(1), 66-66.
[iv] Krassioukov, A., Eng, J. J., Claxton, G., Sakakibara, B. M., & Shum, S. (2010). Neurogenic bowel management after spinal cord injury: a systematic review of the evidence. Spinal cord, 48(10), 718-733.
[v] Ebert, E. (2012). Gastrointestinal involvement in spinal cord injury: a clinical perspective. Journal of Gastrointestinal & Liver Diseases, 21(1).
[vi] Hughes M. (2014). Bowel management in spinal cord injury patients. Clinics in colon and rectal surgery, 27(3), 113–115. https://doi.org/10.1055/s-0034-1383904
[vii] Hocevar, B., & Gray, M. (2008). Intestinal diversion (colostomy or ileostomy) in patients with severe bowel dysfunction following spinal cord injury. Journal of Wound Ostomy & Continence Nursing, 35(2), 159-166.
[viii] Gurcay, E., Bal, A., Eksioglu, E., & Cakci, A. (2010). Quality of life in patients with spinal cord injury. International Journal of Rehabilitation Research, 33(4), 356-358.