Neurogenic Bowel

How bowel control normally works

Stool moves through the colon by waves of muscle contraction controlled by the gut's own nerves and by signals from the spinal cord. When the rectum fills, nerves send a message to the brain, and you choose when to relax the anal sphincter. Damage anywhere in this pathway disrupts movement, sensation or sphincter control.

Types of neurogenic bowel

Causes

• Spinal cord injury: the most studied cause
• Spina bifida
• Multiple sclerosis
• stroke, brain injury and cerebral palsy
• Parkinson's disease
• diabetic autonomic neuropathy
• cauda equina syndrome and pelvic surgery

Symptoms and effects

• constipation, hard stools, infrequent bowel movements
• fecal incontinence (bowel accidents)
• reduced or absent sensation of needing to go
• long time spent on bowel care
• bloating, belly pain and loss of appetite
• hemorrhoids and anal fissures
• autonomic dysreflexia triggered by a full bowel in people with high spinal cord injuries

Neurogenic bowel often occurs together with neurogenic bladder.

Assessment

A rehabilitation specialist, gastroenterologist or nurse will review your bowel history, diet, fluids, mobility, hand function, medicines and current routine, and examine the abdomen and rectum (sensation, reflexes, sphincter tone). Tests may include an abdominal X-ray for stool load, colonic transit studies, and anorectal manometry. A bowel diary of timing, consistency (using the Bristol Stool Chart), accidents and time taken is very helpful.

The bowel program

A bowel program is a planned routine that empties the bowel at a predictable time to prevent accidents and constipation.

1. Timing: same time each day or every other day, often 20 to 30 minutes after a meal to use the gastrocolic reflex.
2. Position: sitting upright on a commode or toilet if possible; otherwise side-lying on the left.
3. Trigger: - reflexic bowel: a stimulant suppository (bisacodyl) or mini enema, followed by digital rectal stimulation (a gloved, lubricated finger gently circled in the rectum) every 5 to 10 minutes until emptying is complete - areflexic bowel: manual evacuation of stool with a gloved finger, often once or twice daily
4. Assistive techniques: abdominal massage, leaning forward, Valsalva if safe.
5. Stool consistency: soft and formed for reflexic bowel, firmer for areflexic bowel.

Supporting measures

• Fiber and fluids: adjust fiber gradually; drink enough, balancing bladder management.
• Medicines: stool softeners, osmotic laxatives (polyethylene glycol), stimulant laxatives such as senna, timed to the program.
• Physical activity as possible.
• Review medicines that constipate, such as opioids and anticholinergics.

When the basic program is not enough

• Transanal irrigation: water instilled through the anus with a balloon catheter to flush the bowel; reduces accidents and time spent.
• Antegrade continence enema (ACE or Malone procedure): a small opening in the abdomen for flushing from above, common in spina bifida.
• Colostomy: can greatly reduce care time and improve quality of life for some people.
• Sacral nerve stimulation in selected cases.

Complications

• fecal impaction and overflow leakage
• hemorrhoids, fissures and rectal prolapse
• autonomic dysreflexia
• pressure injuries and skin breakdown
• reduced quality of life and social isolation

Frequently asked questions

What is neurogenic bowel?

Neurogenic bowel is a loss of normal bowel control caused by nerve damage from conditions such as spinal cord injury, spina bifida, multiple sclerosis or stroke. It typically causes constipation, bowel accidents and difficulty sensing when to go.

What is the difference between reflexic and areflexic bowel?

Reflexic bowel results from damage above the lower spinal cord; reflexes still work, so the rectum empties when stimulated. Areflexic bowel results from damage to the lower cord or nerves; reflexes are lost, the sphincter is weak, and stool must usually be removed manually.

What is a bowel program?

A bowel program is a scheduled routine to empty the bowel at the same time each day or every other day. It combines diet, fluids, medicines, positioning, suppositories and techniques such as digital stimulation or manual evacuation to prevent accidents and constipation.

How long should a bowel program take?

Ideally, a bowel program takes less than about 30 to 60 minutes. If it regularly takes longer, or accidents are frequent, the program should be reviewed with a nurse or doctor to adjust timing, medicines or technique.

Can neurogenic bowel cause autonomic dysreflexia?

Yes. In people with spinal cord injury at T6 or above, a full bowel or bowel care can trigger autonomic dysreflexia, a sudden dangerous rise in blood pressure with headache and flushing. It must be treated promptly by removing the trigger.