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QSCIS
Queensland Spinal Cord Injuries Service

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.

A video demonstration of an assessment of anal reflexes.

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.

Injury occurs in the cord above the conus (T12-L1 level). There is generally loss of voluntary control below the level of injury (pending neurological impairment).
Stimulus eg. Filling bladder, stool in lower rectum, touched on leg
Muscle
Reflex stimulated at cord
Spasm triggered at muscle and muscles contract eg destrusor, bladder or bowel sphincters spasm closed, skeletal muscles
A diagram showing the spinal cord highlighting the Level of Injury above T12/L1.

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.

Injury occurs below cord at conus (T12/L1). There is generally loss of voluntary control below level of voluntary control below level of injury (pending neurological impairment).
Stimulus eg. Filling bladder, stool in lower rectum, touched on leg
Muscle
No reflex activity
Flaccid paralysis eg. low tone of detrusor, bladder or bowel sphincters, skeletal muscles
A diagram showing the spinal cord highlighting the Level of Injury below T12/L1.