Overview
Definition:
Spina bifida is a birth defect in which the spinal cord does not close properly
A neurogenic bowel is a common complication, characterized by impaired bowel control due to abnormal nerve signaling from the spinal cord to the bowel and anal sphincters
This leads to problems with stool storage and evacuation.
Epidemiology:
Spina bifida affects approximately 1 in 2,500 live births worldwide
The incidence varies by geographic location and ethnicity
Approximately 80-90% of individuals with spina bifida experience some degree of neurogenic bowel dysfunction
This is a significant long-term health issue impacting quality of life.
Clinical Significance:
Effective management of neurogenic bowel is crucial for improving the quality of life of individuals with spina bifida
Uncontrolled bowel symptoms can lead to social isolation, recurrent urinary tract infections (UTIs), skin breakdown, and significant parental stress
A well-structured neurogenic bowel program aims to achieve predictable, socially acceptable bowel movements and prevent complications.
Clinical Presentation
Symptoms:
Difficulty with voluntary defecation
Fecal incontinence or soiling
Constipation with overflow incontinence
Abdominal distension and discomfort
Straining or incomplete evacuation
Urgency or accidents
Poor anal sphincter tone on examination.
Signs:
Abnormal spinal cord morphology visible on imaging
Palpable fecal impaction in the rectum
Reduced or absent anal tone
Sacral dimple or tuft of hair indicating spinal dysraphism
Presence of other neurological deficits.
Diagnostic Criteria:
Diagnosis is based on clinical presentation in conjunction with the known diagnosis of spina bifida
Objective assessment of bowel function, including frequency of stools, episodes of incontinence, and effectiveness of evacuation, is key
No single standardized diagnostic criterion exists beyond the presence of spina bifida and the characteristic bowel symptoms.
Diagnostic Approach
History Taking:
Detailed history of bowel habits: frequency, consistency, volume of stools
Timing of onset of symptoms
History of constipation and straining
Episodes of fecal incontinence (timing, triggers)
Previous bowel management strategies and their effectiveness
Associated urinary symptoms
Family history of neural tube defects or bowel issues
Nutritional intake and fluid consumption.
Physical Examination:
General assessment for overall health status
Detailed neurological examination focusing on lower extremities, sensation in the sacral area, and lower limb motor function
Abdominal examination for distension, palpable masses, and bowel sounds
Digital rectal examination to assess anal tone, presence of stool, rectal vault distension, and mucosal integrity
Examination of the skin for pressure sores, especially over bony prominences and the sacral area.
Investigations:
Abdominal X-ray to assess for fecal loading and colonic transit time if constipation is severe
Ultrasound of the abdomen and pelvis may be used to assess for stool burden and rule out other intra-abdominal pathology
Urodynamic studies are often performed concurrently to assess bladder function, as bladder and bowel dysfunction are frequently related in spina bifida
Colonoscopy or sigmoidoscopy may be indicated in select cases to assess for structural abnormalities or proctitis, especially if bleeding is present.
Differential Diagnosis:
Functional constipation in children without spina bifida
Irritable bowel syndrome
Inflammatory bowel disease
Hirschsprung disease (though typically presents earlier)
Other spinal cord abnormalities affecting bowel innervation.
Management
Initial Management:
Establish a multidisciplinary team including pediatric gastroenterologists, neurologists, urologists, surgeons, nurses, dietitians, and physical therapists
Educate the family about the condition and the goals of the bowel program
Initiate a structured bowel program tailored to the individual child's needs.
Medical Management:
Dietary modifications: adequate fiber intake (fruits, vegetables, whole grains) to promote regular bowel movements and prevent constipation
Adequate fluid intake to soften stools
Pharmacological agents: Stool softeners (e.g., docusate sodium, polyethylene glycol)
Stimulant laxatives (e.g., senna, bisacodyl) for timed evacuation
Lubricants (e.g., mineral oil) for difficult stool passage
Prokinetic agents may be considered in select cases
Antimicrobials for associated UTIs.
Surgical Management:
Surgery is reserved for severe cases refractory to conservative management or when complications like severe rectal prolapse or anal strictures are present
Options may include antegrade continence enema (ACE) procedures (e.g., MACE - Malone Antegrade Continence Enema), colostomy, or rectovaginal fistulas repair
Spinal decompression or tethered cord release may be considered if these conditions contribute to bowel dysfunction.
Supportive Care:
Bowel training: establishing a daily routine for attempting bowel movements, often after meals to utilize the gastrocolic reflex
Positional therapy: sitting on a toilet or commode for a set period (e.g., 15-20 minutes) after meals
Skin care: meticulous hygiene to prevent irritation and breakdown from incontinence
Regular monitoring for UTIs and skin breakdown
Psychological support for the child and family
Nutritional counseling to optimize intake for bowel function.
Complications
Early Complications:
Fecal impaction leading to bowel obstruction or pseudo-obstruction
Severe abdominal distension
Anal fissures or tears
Skin breakdown from chronic soiling.
Late Complications:
Recurrent urinary tract infections due to incomplete bladder emptying and fecal contamination
Social and emotional difficulties for the child
Chronic pain
Malnutrition or malabsorption
Rectal prolapse
Autonomic dysreflexia (in higher spinal lesions).
Prevention Strategies:
Consistent adherence to the prescribed bowel program
Regular monitoring of stool consistency and frequency
Prompt treatment of constipation and fecal impaction
Meticulous skin care
Close collaboration with the multidisciplinary team
Early identification and management of UTIs.
Prognosis
Factors Affecting Prognosis:
Level and extent of spinal cord involvement
Presence and severity of other neurological deficits
Adherence to the bowel management program by the patient and family
Availability of multidisciplinary support
Early initiation of a structured program
Co-existing bladder dysfunction.
Outcomes:
With a well-managed neurogenic bowel program, many individuals can achieve social continence, leading to improved self-esteem and participation in daily activities
The goal is predictable bowel movements and prevention of soiling, rather than complete voluntary control for all
Lifelong management is typically required.
Follow Up:
Regular follow-up with the multidisciplinary team is essential
This typically includes annual or semi-annual visits to assess bowel function, monitor for complications (UTIs, skin breakdown), review medications, and adjust the bowel program as needed
As the child grows, the program may need to be adapted to accommodate changes in diet, activity, and independence.
Key Points
Exam Focus:
The neurogenic bowel program for spina bifida is a cornerstone of holistic management
Understand the interplay between bowel and bladder dysfunction
Key management components include diet, fluids, laxatives, and timed evacuation
ACE/MACE procedures are important surgical considerations for refractory cases.
Clinical Pearls:
Emphasize family education and empowerment
The gastrocolic reflex is a valuable ally
encourage attempts at defecation after meals
Differentiate between constipation and overflow incontinence
Multidisciplinary approach is non-negotiable for success
Long-term adherence and consistent follow-up are paramount.
Common Mistakes:
Underestimating the psychological and social impact of bowel dysfunction
Inconsistent implementation of the bowel program
Failure to adequately address bladder dysfunction concurrently
Relying solely on pharmacological management without considering diet, fluids, and behavioral strategies
Dismissing parental concerns or observations about their child's bowel habits.