Neurogenic bowel dysfunction (NBD) is a common issue affecting individuals with neurological disorders such as spinal cord injuries, multiple sclerosis, and stroke, leading to constipation and fecal incontinence. The control of bowel function involves multiple nervous systems, and dysfunction results from damage to specific neural pathways. Management strategies include bowel retraining, dietary adjustments, medications, and in severe cases, surgical interventions.

1. BOWEL
DYSFUNCTION
Dr. Madhu(PT)

2. Introduction
 Bowel dysfunction in neurological conditions,
commonly referred to as neurogenic bowel
dysfunction (NBD), is a frequent complication in
patients with neurological disorders, such as
spinal cord injuries (SCI), multiple sclerosis (MS),
stroke, and Parkinson's disease.
 It manifests primarily as constipation, fecal
incontinence, or a combination of both.
 NBD can significantly affect the quality of life,
leading to physical discomfort, psychological
distress, and complications such as fecal
impaction, rectal prolapse, and autonomic
dysreflexia (in SCI patients).

3. Physiology of Bowel
Control
 The normal control of bowel function is
governed by the coordination of the
*enteric nervous system (ENS),
autonomic nervous system (ANS), and
somatic nervous system, with input from
the central nervous system (CNS).
 The CNS regulates voluntary control over
defecation, while the ANS regulates
involuntary processes such as peristalsis
and sphincter control.

4. Physiology of Bowel
Control
1. Autonomic Nervous System (ANS):
- Sympathetic System (T10-L2): Inhibits bowel
motility and contracts the internal anal sphincter,
aiding in stool retention.
- Parasympathetic System (S2-S4): Promotes bowel
motility (peristalsis) and relaxes the internal anal
sphincter, allowing for defecation.
2. Somatic Nervous System: - The pudendal nerve
(S2-S4) controls the external anal sphincter,
allowing voluntary control over defecation.

5. Physiology of Bowel
Control
3. Central Nervous System (CNS):
- The cerebral cortex is responsible for the
conscious decision to defecate.
- The spinal cord plays a key role in integrating
signals between the brain and the bowel.
 The rectoanal inhibitory reflex: When the rectum
becomes filled with stool, the internal sphincter
reflexively relaxes, signaling the need to defecate.
Conscious control over the external sphincter
allows voluntary postponement of defecation.

6. Pathophysiology of
Neurogenic Bowel
Dysfunction
 Bowel dysfunction occurs when there is
damage to any part of the neurological
pathway involved in bowel control. The
nature of the dysfunction depends on
whether the injury affects upper motor
neurons (UMN) or lower motor neurons
(LMN) :

7. Pathophysiology
1. Upper Motor Neuron (UMN) Neurogenic
Bowel: -
- Occurs when the damage is above the conus
medullaris (above T12).
- Characterized by a spastic or reflexic bowel: the
reflexive peristalsis and sphincter contraction
are intact, but voluntary control is impaired.
- Patients may have difficulty initiating
defecation, but reflex defecation may occur
when the rectum is full.
- Common in spinal cord injuries above T12,
multiple sclerosis, and stroke.

8. Pathophysiology
2. Lower Motor Neuron (LMN) Neurogenic
Bowel:
- Occurs when the damage is to the sacral spinal
cord (S2-S4) or peripheral nerves.
- Characterized by a flaccid or areflexic bowel:
loss of peristalsis and reflexive control, leading
to slow colonic transit and severe constipation.
- The external sphincter is flaccid, often leading to
fecal incontinence.
- Common in cauda equina syndrome and sacral
cord injuries.

9. Clinical Presentation
1. Constipation:
- Difficulty passing stool due to impaired peristalsis
and reduced colonic transit time.
- May lead to abdominal discomfort, bloating, and
fecal impaction.
2. Fecal Incontinence:
- Involuntary leakage of stool due to loss of sphincter
control or incomplete evacuation of stool, which
leads to overflow incontinence.
3. Incomplete Evacuation: - Patients may feel that
their bowel is not completely emptied, leading to
frequent but ineffective attempts to defecate.

10. Clinical Presentation
4. Abdominal Distension:
- Abdominal bloating and discomfort are common
due to accumulated stool and gas.
5. Autonomic Dysreflexia (in SCI patients above T6):
- Life-threatening condition triggered by rectal
distension due to constipation or fecal impaction,
causing an excessive autonomic response (e.g.,
high blood pressure, headache, sweating).BCZ of
uninhibited sympathetic nervous system.

11. Etiology
1. Spinal Cord Injury (SCI):
- The level of injury dictates whether the
patient will have a reflexic or areflexic bowel.
- Reflexic bowel is typical in injuries above T12;
areflexic bowel is seen in injuries below T12.
2. Multiple Sclerosis (MS): - MS lesions can
affect bowel control pathways, leading to a
combination of constipation and fecal
incontinence.

12. Etiology
3. Stroke:
- Stroke affecting the cerebral cortex or brainstem
can impair voluntary control over defecation,
leading to constipation and incontinence.
4. Parkinson’s Disease: - Due to autonomic
dysfunction, slow colonic transit and constipation
are common in Parkinson’s disease.
5. Cauda Equina Syndrome: - Involves damage to
the sacral nerve roots (S2-S4), leading to areflexic
bowel and severe constipation with overflow
incontinence.

13. Assessment of Bowel
Dysfunction
1. Patient History:
- Detailed history of bowel habits, including
stool frequency, consistency (Bristol Stool
Scale), and any episodes of incontinence.
- History of neurological disorder and
associated symptoms.
- Impact of bowel dysfunction on quality of life
(physical, emotional, and social aspects).
- Use of medications that may affect bowel
motility (e.g., opioids, anticholinergics).

14. Assessment
2. Physical Examination:
- Abdominal Exam: Palpation for
abdominal distension, tenderness, or
fecal masses.
- Rectal Examination: To assess anal
sphincter tone, presence of stool in the
rectum, and potential for fecal
impaction.
- Neurological Exam: Evaluate sensory
and motor function, particularly in the

15. Assessment
3. Investigations:
- Colonic Transit Studies: To measure the time it
takes for stool to pass through the colon (useful
for diagnosing slow transit constipation).
- Anorectal Manometry: Measures the strength
of the anal sphincter and the rectoanal
inhibitory reflex.
- Barium Enema: To assess for structural
abnormalities in the colon.
- Ultrasound/CT: In cases of suspected megacolon
or severe impaction.

16. Colonic transit study

19. Barium Enema

20. Management of Neurogenic
Bowel Dysfunction
 Conservative Management
1. Bowel Retraining Program:
- Establishing a regular bowel routine
(same time every day) is essential for
patients with neurogenic bowel.
- Digital Stimulation: For reflexic bowel,
manual stimulation of the rectum can
help initiate the defecation reflex.

21. Management
2. Dietary Modifications:
- High-Fiber Diet: Promotes stool bulk and
helps regulate bowel movements.
- Adequate Hydration: Helps soften the
stool and prevent constipation.
- Scheduled Toileting: Encourages
defecation at the same time each day,
often after meals to take advantage of
the gastrocolic reflex.

22. Management
3. Medications:
- Stool Softeners (e.g., docusate): Help soften stool for
easier passage.
- Laxatives: - Bulk-forming agents (e.g., psyllium):
Increase stool bulk and stimulate peristalsis.
- Osmotic laxatives (e.g., lactulose, polyethylene
glycol): Draw water into the bowel to soften stool
and stimulate defecation.
- Suppositories (e.g., glycerin, bisacodyl): For patients
who need rectal stimulation to trigger defecation.
- Enemas: For severe constipation or bowel
preparation, typically used in cases of fecal
impaction.

23. Management
4. Pelvic Floor Muscle Training:
- Strengthening the muscles around the
anus and rectum can help improve
voluntary control of defecation in
patients with partial sphincter control.

24. Advanced Management
1. Transanal Irrigation:
- A mechanical method of emptying the bowel by introducing
water into the colon through the anus to stimulate
peristalsis and evacuation.
- Useful for patients with chronic constipation or
incontinence, particularly in spinal cord injury patients.
2. Electrical Stimulation and Biofeedback:
- Neuromodulation of sacral nerves can be used to improve
colonic motility and sphincter function, particularly in
patients with slow-transit constipation.
- Biofeedback: Used to teach patients how to improve pelvic
floor muscle function and coordination during defecation.

25. Transanal irrigation

26. Surgical Management
1. Colostomy/Ileostomy:
- Creation of an abdominal stoma to divert stool into
an external bag.
- Considered in cases of intractable bowel
dysfunction, where conservative measures fail or are
inappropriate.
- Indicated for patients with severe fecal incontinence,
slow transit constipation, or rectal prolapse.
2. Sphincteroplasty: - Surgical repair of a weakened or
damaged

27. Colostomy