Anorectal examination
A spinal cord injury can be assessed through an anorectal examination. This examination can be done in two ways. These are the peri-anal sensory examination and a digital rectal examination.
Peri-anal sensory examination
The peri-anal examination is required to complete the International Standards for Neurological Classification of Spinal Cord Injury assessment. This involves sensory grading of the S4-5 dermatome for light touch and pin prick.
For more information on how to conduct this assessment:
American Spinal Injury Association, The premier North American organization in the field of Spinal Cord Injury Care, Education, and Research.
Digital rectal examination
A digital rectal examination is to assess deep anal pressure, voluntary anal contraction and anal reflexes.
Deep anal pressure and Voluntary Anal Contraction
The assessment of deep anal pressure and voluntary anal contraction is required to complete the International Standards for Neurological Classification of Spinal Cord Injury assessment.
For more information on how to conduct this assessment:
American Spinal Injury Association, The premier North American organization in the field of Spinal Cord Injury Care, Education, and Research.
International standards for neurological classification of spinal cord injury (ISNCSCI) worksheet – This is commonly referred to as the ASIA form
Anal Reflexes
This examination is not required for an The International Standards for Neurological Classification of Spinal Cord Injury assessment; however this enables differentiation between upper motor neurone and lower motor neurone spinal cord injuries and spinal shock and is, therefore important for determination of an appropriate bowel management plan.
Explain to the person
Check person identification. Explain to the person that a gloved and lubricated finger will be inserted 2-3 cm into the rectum.
Assess anal reflexes
For anal wink:
- Encourage anal sphincter contraction with pin prick stimulation of the mucocutaneous junction of the anus.
For bulbocavernosus reflex:
- Encourage anal sphincter contraction with a gentle squeeze of the glans penis or clitoris or a gentle tug on the urethral catheter.
In the case of an upper motor neurone spinal cord injury, reflexes will be present.
In the case of a lower motor neurone spinal cord injury or during spinal shock, reflexes are absent.
Spinal shock
Spinal shock is a phenomenon of temporary loss of all or most reflex activity as a result of a high level spinal cord injury usually T6 and above.
Spinal shock typically lasts for 48 to 72 hours and sometimes for weeks or months.
A spinal shock can cause an areflexic rectum and anus and absent colon peristalsis resulting in paralytic ileus.
Upper motor neurone injury
An upper motor neurone (UMN) type bowel most commonly occurs in people with spinal cord injuries above T12/L1. The presentation of this type of bowel is influenced by the intact action of the defaecation reflex centre, which causes an involuntary spasm - like contraction of the muscles of the rectum and anus.
However, due to disruptions in the message pathways up and down the spinal cord due to spinal cord injury, people with UMN spinal injuries are unable to control the relaxing of this muscle to allow or prevent defaecation. They also may have difficulty determining whether their bowel is full, has already evacuated, or if wind or solid matter has been passed.
Left untreated, people with UMN bowels will likely experience chronic constipation and recurring unplanned bowel movements. This can impact other facets of key health, work and social life, as well as personal relationships.
Lower motor neurone injury
Lower motor neurone (LMN) or Cauda Equina Syndrome (CES) type bowel most commonly occur in people with spinal cord injuries at or below T12/L1. The messages to the defaecation reflex centre (which is below T12/L1) are disrupted.
This results in a flaccid bowel as the reflex centre does not exert any influence over the anal and rectal muscles. This means people with LMN spinal injuries generally have:
- poor or no anal tone
- loss of voluntary control
- poor or no sensation of the lower bowel to know when it is full or when an evacuation has occurred
- decreased peristalsis.
Left untreated, people with LMN bowels can experience chronic constipation and unplanned bowel movements.
Uncontrolled bowel motions (faecal incontinence) increase the risk of skin breakdown as well as including problems with incontinence associated dermatitis (IAD). The stool contacting the skin causes overhydration and increased pH of the skin. This can impact other facets of key health, work and social life, as well as personal relationships.
