Spinal cord injury (SCI) - bladder and bowel function

The majority of individuals with SCI experience significant symptoms related to neurogenic bowel dysfunction. For example, 42% experience constipation and as many as 77% experience fecal incontinence.

A spinal cord injury (SCI) can occur at any level of the spinal cord. It can either be a complete injury, with a total loss of sensation and muscle function or incomplete, meaning some muscle control and feeling may remain. An SCI usually affects control over the bladder and bowel but depending on the level and completeness of the lesion, different symptoms occur. Three nerves are important for controlling the function of the bladder and bowel.


The nerves involved in bladder and bowel control are the hypogastric, pelvic, and pudendal nerves.

People with SCI experience neurogenic bowel problems, which increase with age and duration.

Higher lesions will result in slower colon transit times, up to double ‘normal healthy’ transit. This will lead to constipation and fecal retention/impaction.  

An SCI above T12 would typically result in a reflex bowel with the following symptoms:

  • Loss of sensation when the bowel is full. The message between the bowel and the central nervous system (CNS) usually telling the bowel that it is full is not received
  • Will continue to empty when stimulated
  • A high rectal pressure
  • The muscle controlling the opening and closing of the anus stays tight
  • When the bowel gets full, it empties automatically, i.e. predisposes to inappropriate emptying

An SCI below T12 would typically result in a flaccid bowel, with the following symptoms:

  • Loss of sensation when the bowel is full
  • It Will not fully empty, even when stimulated. This is because the SCI has damaged the pathways from the bowel into the reflex center in the spine, i.e. there cannot be any reflex action
  • The rectal pressure is low
  • Predisposes to bowel soiling, i.e. fecal incontinence

The proximity of the bladder and bowel means that functional interaction is inevitable. It is therefore important to remember that some of the bladder and/or bowel symptoms may have a correlation, e.g. urinary leakage due to constipation.

Since there is such a close connection between the bladder and bowel, and problems arising in one area might also affect the other, it is important to remember to address them both to increase the quality of life for the person affected.

The emotional and psychological impact of bowel problems with SCI can be devastating. Therapies should be aimed at understanding the physiological mechanisms, and tailoring treatments toward symptom management.