Organic Causes of Constipation in Children

Educational Objectives

The goal of this program is to improve management of constipation in children. After hearing and assimilating this program, the clinician will be better able to:

1. Identify patients with an organic cause of constipation.
2. Recognize “red-flag” signs of an underlying organic cause of constipation.

Summary

Overview: constipation is the subjective complaint of passing abnormally delayed or infrequent dry hardened stool; normal frequency of bowel movements varies by age; functional constipation should be differentiated from organic constipation; “red-flag” signs for organic causes include fever or constitutional symptoms (which indicate systemic disease), nausea and vomiting (which indicate bowel obstruction), and alternating constipation and diarrhea with bloody stools (which indicates inflammatory bowel disease until proven otherwise); in infants, constipation associated with delayed passage of meconium is Hirschsprung disease until proven otherwise (accentuated anal tone may be present); perianal fissures, erythema, and fistula can be mechanical causes and can cause stool-holding behavior; absence of anal wink with constipation, poor urinary flow, or weakness in the lower extremities could indicate spina bifida or tethering of the spinal cord; presence of a sacral tuft of hair is spina bifida until proven otherwise

Anatomy of the enteric nervous system: the extrinsic nerves originate from the vagus nerve and fibers extending from the sympathetic ganglia along the spine; intrinsic nerves are divided between the myenteric plexus and submucous plexus; nerves originate from neural crest cells that migrate and populate the plexus, establishing communications between dendrites and axons along their planes; plexus also intercommunicate and allow for the synchronous activation of neurons and normal bowel motility and contractility

Nonorganic causes: developmental issues include infant dyschezia (lack of development of normal synchrony); older children with attention-deficit/hyperactivity disorder may have premature rectal contraction and release of the internal anal sphincter; situational issues include difficulty toilet training, toilet phobia, and avoidance of school bathrooms; sexual abuse should be considered as a possible cause; aggressive treatment is needed if proximal bowel dilation and colonic inertia occurs

Organic causes: include anal stenosis or anterior anus, acquired anal strictures in inflammatory bowel disease, colon strictures in prematurity with necrotizing enterocolitis, spinal cord lesions, congenital aganglionosis (Hirschsprung disease), dysplasticity of nerves, metabolic causes, systemic disorders, cystic fibrosis, hormonal abnormalities, and inflammatory and rheumatologic disorders of muscle and connective tissues; various drugs can also cause constipation

Diagnostic workup: may include serum electrolyte levels, thyroid function, and celiac panel; imaging includes abdominal x-ray, barium enema, magnetic resonance defecography, and computed tomography; barium enema without bowel preparation can identify the transition zone; magnetic resonance imaging of the lumbosacral spine can identify spina bifida and tethering of spinal cord; ingestion of 24 radio-opaque markers gives a qualitative assessment of intestinal transit; passage of ≥80% of the markers within 3 days is expected; homogeneous distribution of markers in the colon on x-ray indicates colonic inertia; markers coalesced in the rectosigmoid area mixed with stool indicates fecal retention or outlet dysfunction; if Hirschsprung disease is suspected, anal manometry is done; failure to relax the internal sphincter on rectal dilation through placement of a rectal balloon is typical and may be associated with paradoxical contraction of the external anal sphincter; histologic diagnosis is by biopsy of the submucosa; anal sphincter electromyography is done under general anesthesia to evaluate function of external anal sphincter in children with anorectal anomalies undergoing reimplantation surgery

Hirschsprung disease: often involves the rectosigmoid area, is more prevalent in male children, and is associated with chromosomal abnormalities; can present with severe enterocolitis in infancy with extensive bloody diarrhea; excessive obstruction and abdominal distension can lead to food refusal and failure to thrive; a gush of air and liquid is seen on digital rectal examination

Magnetic resonance defecography: is useful in adolescents with outlet dysfunction because it allows visualization of the pelvic anatomy and pelvic floor; barium is placed in the rectum to stimulate contraction; visualized synchrony gives a qualitative assessment of defecation

Fecal incontinence: or encopresis, is defined as incontinence of stool not resulting from organic defect or illness; mean age of presentation is 7 to 9 yr with a male-to-female predominance of 2:1; parents should be counseled that incontinence is involuntary; dilation of the rectum, thinning of the anorectal space, and dilation of the sphincters leads to incontinence of both liquid and stool; return to normal anatomy and integrity helps to establish continence

Management: disimpaction is important in patients with severe idiopathic constipation and significant fecal retention; oral polyethylene glycol or rectal disimpaction with sodium phosphate enema, saline enema, or SMOG (saline, mineral oil, and glycerin) enema can be given; manual disimpaction is reserved for patients who fail medical therapy and is usually done under general anesthesia; maintenance therapy is with polyethylene glycol either alone or in conjunction with stimulants such as bisacodyl or senna glycoside; behavioral modification therapy is used in conjunction with medical therapy; magnesium products are avoided because of hypermagnesemia and other adverse effects; lubricants such as mineral oil are not favored in children <1 yr and in those with neurocognitive issues because of the risk for aspiration pneumonia; stimulants can be given with osmotic agents in patients with significant bowel dilation; a cecostomy or appendicostomy can be done in refractory constipation with colonic dilation and inertia to allow provision of antegrade enemas

Readings

Ambartsumyan L et al. Diagnosis of Hirschsprung disease. Pediatr Dev Pathol. 2020; 23(1):8-22. doi:10.1177/1093526619892351; Nurko S and Zimmerman LA. Evaluation and treatment of constipation in children and adolescents. Am Fam Physician. 2014; 90(2):82-90; van den Berg MM et al. Epidemiology of childhood constipation: a systematic review. Am J Gastroenterol. 2006; 101(10):2401-2409. doi:10.1111/j.1572–0241.2006.00771.x.

Disclosures

In adherence to ACCME Standards for Commercial Support, Audio Digest requires all faculty and members of the planning committee to disclose relevant financial relationships within the past 12 months that might create any personal conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, members of the faculty and planning committee reported nothing to disclose.

Acknowledgements

Dr. Cuffari was recorded virtually at the 47th Annual Pediatric Trends, held May 11-14, 2021, and presented by Johns Hopkins University School of Medicine, Baltimore, MD; and Johns Hopkins Children's Center, Baltimore. For information on future CME activities from this presenter, please visit https://hopkinscme.cloud-cme.com. Audio Digest thanks the speakers and the Johns Hopkins University School of Medicine for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

PD674502

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.