Bowel dysfunction.pptx...................
- 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.
- 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.
- 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