CONSTIPATION

CONSTIPATION

  1. 1
    Current Diagnosis
    • While constipation is a benign process, it is important to recognize signs of a serious condition.
    • Classification of normal transit constipation, slow transit constipation, or pelvic floor dysfunction guides therapy.
    • Clinical testing has low benefit, but colonoscopy or imaging can assess for organic causes.
  2. 2
    Current Therapy
    • Initial therapy includes soluble dietary fiber to improve symptoms in chronic constipation.
    • Osmotic laxatives are preferred while utilizing stimulant laxatives as rescue agents.
    • Surgery is reserved for pelvic floor dysfunction after optimal therapies have failed.
  3. 3
    Epidemiology

    Constipation is common, with a prevalence of 1.9% to 27.2%, but the description of symptoms is variable. A thorough history and focused physical examination aids diagnosis. Treatment is directed toward relief of symptoms, alleviation of precipitating factors, and prevention of recurrence. While constipation is a benign process, it is important to recognize concerning signs for a more serious medical condition such as malignancy.

  4. 4
    Risk Factors

    Vulnerable populations include female, elderly, neurodegenerative disease, low-fiber diet, painful rectal disorders, hypothyroidism, and diabetes mellitus.

  5. 5
    Pathophysiology

    With aging, there is decreased rectal compliance, diminished rectal sensation, and decreased resting anal pressures, while colonic transit time is preserved. Normal transit constipation is a component of irritable bowel syndrome with normal transit time and stool frequency. Slow transit constipation is a condition with colonic dysmotility resulting from altered enteric nervous system. Defecatory disorders include structural disturbances of the pelvic floor. Pelvic floor dysfunction is the paradoxical contraction of the external anal sphincter and puborectalis muscles during defecation. Secondary causes of constipation are listed in Table 1.

    Table 1

    Causes of Constipation

    Dietary Low-fiber diet, dementia, depression, anorexia, dehydration
    Metabolic Diabetes mellitus, hypercalcemia, hypokalemia, hypothyroidism, systemic sclerosis
    Neurologic Parkinson’s disease, spinal cord disorder, multiple sclerosis, cerebrovascular disease (stroke)
    Iatrogenic Antacids, iron, anticholinergics, antidepressants, antipsychotics, opiates, antiepileptics
    Painful anorectal condition Anal fissure, hemorrhoids, abscess, fistula, pelvic floor dysfunction, malignancy
  6. 6
    Prevention

    Provide an environment of privacy and comfort to allow for natural defecation. Prescribe an adequate fluid and fiber intake with specific amounts that vary depending on the patient’s condition. Encourage physical activity, with a low to moderate level of exercise depending on the patient’s functional status. Develop a routine for defecation with a prompt response to a call to defecate urgently. Recurrent fecal impaction can be prevented with polyethylene glycol (PEG, MiraLax).

  7. 7
    Clinical Manifestations

    Patients will complain using qualitative terms of hard stools, a feeling of incomplete voiding, straining, prolonged time for laxation, the need for additional maneuvers, abdominal bloating, and abdominal pain (Table 2). A change in bowel habit differentiates the current complaint from a serious medical condition. Red flags include acute onset, weight loss, abdominal pain or cramping, rectal bleeding, nausea or vomiting, rectal pain, fever, or a change in stool caliber. Infants with abdominal distension and failure to pass meconium within 24 hours indicate Hirschsprung’s disease. Patients should be asked if they have had loose stools or bowel incontinence to assess for fecal impaction. A medication review is required (see Table 1). Classification of patients with normal transit constipation, slow transit constipation, or pelvic floor dysfunction/defecatory disorders guides therapy.

    Table 2

    Rome III Criteria

     

     

     

  8. 8
    Diagnosis

    Diagnostic criteria have been established because the symptoms can vary (see Table 2). Conduct a physical examination that includes an assessment of vital signs, weight, volume status, auscultation of bowel sounds, abdominal percussion for tympani, and abdominal palpation for tenderness or mass. A rectal examination can detect resting rectal tone, fecal impaction, anorectal disorders, or rectal mass. Defecatory disorders show an increased resistance to the insertion of the examiner’s finger with an impaired relaxation of the sphincter complex and reduced perineal descent during a Valsalva maneuver.

    Conduct laboratory testing on electrolytes, hemoglobin, thyroid- stimulating hormone, and fecal occult after initial measures fail. Red flag symptoms require imaging with CT of the abdomen and pelvis or an endoscopy to diagnose malignancy or fecal impaction. Anorectal testing with manometry and a rectal balloon expulsion test is appropriate for pelvic floor dysfunction or defecatory disorders.

    Hirschsprung’s disease is diagnosed with barium enema, rectal manometry, or a rectal suction biopsy. Colonic transit rates with radiopaque markers (Sitz) on serial abdominal radiographs over 4 to 7 days diagnose slow transit constipation disorders.

     

  9. 9
    Treatment

    Nonpharmacologic therapies have limited benefit. Unless there are signs of dehydration, increasing fluid intake is not indicated.

    Moderate-intensity exercise improves symptoms of irritable bowel syndrome. Probiotics are not beneficial.

    There is moderate evidence for pharmacologic agents (Table 3).

    Normal transit constipation responds to soluble dietary fiber supplements (e.g., psyllium [Metamucil]); however, these should not be used in the case of slow transit constipation or drug-induced constipation. Osmotic agents with PEG (Miralax) or lactulose (Chronulac) can be dose increased for soft stools. Stimulant laxatives are used as rescue therapy if patients do not have a bowel movement for 2 days.

    Table 3

    Drug Dosing and Adverse Effects

    • Not FDA approved for this

    †  Available as dietary supplement.

    New classes of drugs to manage constipation include intestinal secretagogues, serotonin 5-HT4 receptor antagonists, and opiate antagonists. Lubiprostone (Amitiza) requires a negative pregnancy test with contraception. Linaclotide (Linzess) is a 14-amino acid peptide similar to heat-stable enterotoxins that cause diarrhea.

    Lubiprostone and linaclotide are FDA-approved for chronic idiopathic constipation and irritable bowel syndrome with constipation.

    Plecanatide (Trulance) is a newly approved drug for chronic idiopathic constipation in adults. It is a guanylate cyclase-C agonist that increases fluid secretion into the upper intestine.

    Methylnaltrexone (Relistor) and naloxegol (Movantik) are opiate receptor antagonists that can cause laxation in patients on chronic opiate therapy.

    Pelvic floor dysfunction or defecatory disorders respond to biofeedback therapy by utilizing manometry and visual or auditory feedback. Patients practice expelling a balloon and improve pelvic floor muscle coordination with Kegel exercises. Surgical intervention with subtotal colectomy with ileorectal anastomosis is indicated for slow transit constipation or defecatory disorders after failure of optimal medical management.

     

  10. 10
    Complications

    Fecal impaction a complication and a large bowel obstruction with colonic perforation has high mortality. Pediatric and geriatric patients are most susceptible with signs and symptoms of fecal incontinence, abdominal pain, abdominal distention, anorexia, weight loss, and delirium. Treatments for adults include a large-volume tap-water enema (500–1000 mL), local anesthetics administered topically with abdominal massage, a colonoscopy, or surgery. The prevention of recurrence requires maintenance bowel regimen with osmotic agents such as PEG (Miralax).

     

  11. 11
    References
    • Arshad A., Powell C. Easily missed? Hirschsprung’s disease. Br Med J. 2012;345:e5521.
    • Bharucha A.E., Pemberton J.H., Locke G.R. American Gastroenterological Association technical review on constipation. Gastroenterology. 2013;144:218–238.
    • Gallagher P.F., O’Mahony D., Quigley E.M. Management of chronic constipation in the elderly. Drugs Aging. 2008;25:807– 821.
    • Higgins P.D., Johanson J.F. Epidemiology of constipation in North America: A systematic review. Am J Gastroenterol. 2004;99:750–759.
    • Larkin P.J., Sykes N.P., Centeno C., et al. The management of constipation in palliative care: Clinical practice recommendations. Palliat Med. 2008;22:796–807.
    • McCallum I.J., Ong S., Mercer-Jones M. Chronic constipation in adults. Br Med J. 2009;338:b831.
    • Thomas J., Karver S., Cooney G.A., et al. Methylnaltrexone for opioid-induced constipation in advanced illness. N Engl J Med. 2008;358:2332–2343.
    • Wald A. Management and prevention of fecal impaction. Curr Gastroenterol Rep. 2008;10:299–501.
    • Gastroenterology. Rome criteria. Available at, http://www.romecriteria.org/. 2006.
    • Wald A. Constipation: Advances in diagnosis and treatment.
    • JAMA. 2016 Jan 12;315(2):185–191.
KNOWLEDGE BASE
About Genomic Medicine UK

Genomic Medicine UK is the home of comprehensive genomic testing in London. Our consultant medical doctors work tirelessly to provide the highest standards of medical laboratory testing for personalised medical treatments, genomic risk assessments for common diseases and genomic risk assessment for cancers at an affordable cost for everybody. We use state-of-the-art modern technologies of next-generation sequencing and DNA chip microarray to provide all of our patients and partner doctors with a reliable, evidence-based, thorough and valuable medical service.

X