INTRODUCTION

Section 2 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Background

Constipation is a symptom rather than a disease and is the most common digestive complaint in the United States. A standard set of criteria has been suggested that includes at least 2 of the following symptoms present for at least 3 months:

• Hard stools
• Straining at defecation
• Sensation of incomplete evacuation at least 25% of the time
• Two or fewer bowel movements per week

Pathophysiology

Constipation results from a colonic or anorectal functional disorder.

Frequency

United States

More than 4 million people have frequent constipation, a prevalence of about 2%. Constipation accounts for an estimated 2.5 million physician visits per year.

Mortality/Morbidity

Most patients with constipation can be treated medically, resulting in complete success or improvement. However, a small percentage of patients are quite debilitated as a result of constipation. Some patients with functional constipation (ie, colonic inertia) require total abdominal colectomy with ileorectal anastomosis.

Race

Constipation appears to affect people of color 1.3 times more frequently than whites.

Sex

Male-to-female ratio is approximately 1:3.

Age

Constipation can occur in all ages, from newborns to elderly persons. An age-related increase in the incidence of constipation exists, with 30-40% of adults older than 65 years citing constipation as a problem.

CLINICAL

Section 3 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

History

• History is most relevant regarding the etiology of constipation. Understanding the type and degree of disability caused by the symptoms is important. Disability may include the following:
• • Length of time attempting rectal evacuation
  • Number of bowel movements per week
  • Presence of chronic straining and/or hard stools
• The patient may be totally asymptomatic or complain of the following:
• • Abdominal bloating
  • Pain on defecation
  • Rectal bleeding
  • Spurious diarrhea
  • Low back pain
• The following also suggest that the patient may have difficult rectal evacuation:
• • Feeling of incomplete evacuation
  • Digital extraction
  • Tenesmus
  • Enema retention
• However, the following signs and symptoms should be concerning:
• • Rectal bleeding
  • Abdominal pain
  • Vomiting
  • Unexplained weight loss

Physical

• General physical examination often is of no benefit in determining etiology or deciding on treatment. The following are exceptional findings:
• • A localized mass on abdominal examination
  • Local anorectal lesions, which can cause or contribute to constipation (eg, anal fissures, fistulae, strictures, cancer, thrombosed hemorrhoids)
  • Visible intussusception during straining
• Digital rectal examination provides information about the following:
• • Anorectal masses
  • Tone of the internal anal sphincter
  • Strength of the external anal sphincter and puborectalis muscle
  • Presence of gross blood or occult bleeding by checking the stool guaiac
  • Stool amount and consistency: In pelvic outlet dysfunction, more stool is present in the rectal vault than in colonic inertia or irritable bowel syndrome, in which little or no stool remains in the rectum between defecations. Pelvic floor dysfunction manifests by failure of descent of the examining finger and contraction of the upper segment of the sphincter during straining.

Causes

The cause of constipation is usually multifactorial.

• Secondary constipation
• • Dietary - Low fiber
  • Structural - Anal fissures, thrombosed hemorrhoids, strictures, and tumors
  • Endocrinopathic and metabolic - Hypercalcemia, hypokalemia, hypothyroidism, diabetes mellitus, and pregnancy
  • Neurologic - Stroke, Hirschsprung disease, Parkinson disease, multiple sclerosis, spinal cord lesion, Chagas disease, and familial dysautonomia
  • Connective-tissue disorders - Scleroderma, amyloidosis, and mixed connective-tissue disease
  • Drugs
    • Antidepressants (cyclic antidepressants, monoamine oxidase inhibitors [MAOIs])
    • Metals (iron, bismuth)
    • Anticholinergics (benztropine, trihexyphenidyl)
    • Opioids (codeine, morphine)
    • Antacids (aluminum, calcium compounds)
    • Calcium channel blockers (verapamil)
    • Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or diclofenac
    • Sympathomimetics (pseudoephedrine)
    • Cholestyramine and stimulant laxatives (long-term use)
    • Antipsychotics
  • Psychologic - Depression
• Functional constipation
• • Simple constipation - Repressed defecatory urge
  • Irritable bowel syndrome
  • Constipation with colonic dilatation - Idiopathic megacolon or megarectum
  • Constipation without colonic dilatation - Idiopathic slow transit constipation
  • Chronic intestinal obstruction
  • Rectal outlet obstruction - Anismus, solitary rectal ulcer, intussusception
  • Weak pelvic floor - Descending perineum, rectocele
  • Ineffective straining

DIFFERENTIALS

Section 4 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Other Problems to be Considered

Diabetes mellitus
Hyperparathyroidism
Hypothyroidism
Lead poisoning
Neuropathy
Parkinson disease
Scleroderma

WORKUP

Section 5 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Lab Studies

• Serum chemistry may exclude any metabolic causes of constipation, such as hypokalemia and hypercalcemia.
• Complete blood count (CBC) may reveal any anemia that might be associated with rectal bleeding (gross or occult).
• Thyroid function tests may be helpful with patients suspected of having hypothyroidism.

Imaging Studies

• Plain film of the abdomen (upright and flat)
• • This study underscores the amount of stool present in a patient's colon. Differentiation of fecal impaction, bowel obstruction, and fecalith is possible.
  • Diagnosis of fecaliths is important because of the dreaded complication of stercoral ulcers, which can lead to colonic perforation.
  • Diabetic gastropathy, as well as fecal impaction, may be seen in patients with diabetic neuropathy.
  • Residual barium (from barium enemas) can be visualized.
  • Scleroderma and other connective-tissue diseases may be complicated by motor disturbances that mimic colonic obstruction on plain film.
  • Myxedema ileus is a consequence of hypothyroidism.

Other Tests

• An extensive workup of the constipated patient is performed on an outpatient basis and usually occurs after approximately 3-6 months of failed medical management.
• These tests are either anatomic (eg, Gastrografin enema, proctosigmoidoscopy, colonoscopy) or physiologic (eg, colonic transit study, defecography, manometry, electromyography).

Procedures

• Anoscopy: Routinely perform anoscopy on all constipated patients to visualize anal fissures, ulcers, hemorrhoids, and local anorectal malignancy.
• Digital disimpaction: A well-lubricated gloved finger might be required in patients with lower anorectal impactions.
• Warm water enemas: These usually are unpopular among the nursing staff and probably are not necessary within the ED.

TREATMENT

Section 6 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Emergency Department Care

• Most patients have chronic constipation, which does not lend itself to a specific etiology at time of presentation.
• A comprehensive history should readily identify the most common causes of fecal impaction including (1) postoperative constipation, (2) prolonged bed rest, (3) residual barium from barium enemas, or (4) medication-related constipation (eg, opioids, anticholinergics).
• In elderly bedridden patients, it is important to exclude severe dehydration and electrolyte abnormalities.
• Exclude any life-threatening complication of constipation (eg, volvulus) and remember that the patient might present with intestinal perforation after tap water enemas performed at home.
• Specifically focus therapeutic interventions on facilitating rectal evacuation rather than increasing bowel movement.

Consultations

• Consult a general surgeon if you suspect intestinal obstruction or volvulus.

MEDICATION

Section 7 of 11  

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• Introduction
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• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

The mainstay of treatment is a high-fiber diet. Bulking agents usually are the next line of treatment. Enemas can be used to assist in complete stool evacuation. Avoid irritant or peristaltic stimulants (eg, senna). Chronic use has been reported to induce damage to the myenteric plexus, which may eventually impair bowel motility.

Drug Category: Bulk-forming agents

These agents are used to increase fecal mass, which stimulates peristalsis.

Drug Category: Emollients or softeners

Lower surface tension of stool and allow mixing of aqueous and fatty substances, thereby softening stool.

Drug Category: Emollient stool softeners in combination with stimulants

Emollient stool softeners cause stool to soften. Stimulants increase peristaltic activity in the GI.

Drug Category: Osmotic laxatives

These agents act by retaining fluid in the bowel, osmosis, or altering the pattern of water distribution in feces.

Drug Category: Gastrointestinal Agent, Miscellaneous

These agents may assist in increasing GI motility.

Drug Category: 5-HT4 Receptor partial agonists

These agents may stimulate peristaltic activity by partially activating serotonin type 4 receptors. Tegaserod was temporarily withdrawn from the US market in March 2007; however, as of July 27, 2007, restricted use of tegaserod is now permitted via a treatment investigational new drug (IND) protocol. The treatment IND will allow tegaserod treatment of irritable bowel syndrome with constipation (IBS-C) or chronic idiopathic constipation (CIC) in women younger than 55 years who meet specific guidelines. Its use is further restricted to those in critical need who have no known or preexisting heart disease.
 
Earlier this year, tegaserod marketing was suspended because of a meta-analysis of safety data pooled from 29 clinical trials that involved more than 18,000 patients. The results showed an excess number of serious cardiovascular adverse events, including angina, myocardial infarction, and stroke, in those taking tegaserod compared with placebo. In each study, patients were assigned at random to either tegaserod or placebo. Tegaserod was taken by 11,614 patients, and placebo was taken by 7,031 patients. The average age of patients in these studies was 43 years, and most patients (ie, 88%) were women. Serious and life-threatening cardiovascular adverse effects occurred in 13 patients (0.1%) treated with tegaserod; among these, 4 patients had a heart attack (1 died), 6 had unstable angina, and 3 had a stroke. Among the patients taking placebo, only 1 (0.01%) had symptoms suggesting the beginning of a stroke that went away without complication. For more information, see the FDA MedWatch Product Safety Alert.

FOLLOW-UP

Section 8 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Further Inpatient Care

• Patients with the following warrant admission and surgical evaluation:
• • Obstructive symptoms
  • Nonrectal impactions
  • Fever and dehydration

Further Outpatient Care

• Further outpatient care should include contact with the primary care provider to ensure follow-up.
• Referral to a gastroenterologist is warranted for patients with the following:
• • Constipation of recent onset
  • Chronic constipation associated with weight loss, anemia, or change in stool consistency
  • Refractory constipation
  • Constipation requiring chronic laxative use
• Future directions
• • Prokinetic agents that stimulate serotonergic enteric nervous system receptors
    
    
    • Tegaserod - As of July 27, 2007, restricted use of tegaserod is permitted via a treatment IND protocol; however, it had been withdrawn from the US market March 30, 2007.
    • Prucalopride
  • Enteric nervous system neurotrophin and opiate
    antagonists
  • Electrical stimulation of the colon
  • Stem cells to repopulate dysfunctional neurons

In/Out Patient Meds

• Bulk-forming agent: Psyllium (eg, Metamucil) increases frequency and softens stool consistency.
• Emollient: Docusate sodium (eg, Colace) improves hard bowel movements.
• Lukewarm tap water enema: This treatment facilitates rapid relief of symptoms and may help regulate further bowel movements.

Deterrence/Prevention

• Adequate fluid intake (ie, eight 8-oz glasses of water per day)
• Regular exercise
• High-fiber diet
• Avoidance or decreased use of constipating medications
• Regular bowel habits with attempted bowel movements at the same time daily may help symptoms, especially after meals when the gastrocolic reflex is strongest.

Complications

• Anal fissures
• Fecal impaction
• Bowel obstruction
• Fecal incontinence
• Stercoral ulceration
• Megacolon
• Volvulus
• Rectal prolapse
• Urinary retention
• Syncope

Prognosis

• Most active patients do well with medical management.
• Constipation is an ongoing problem for patients who are bedridden or otherwise debilitated.
• Colectomy usually is reserved for patients with slow transit constipation who fail to respond to 6 months of medical management with good patient compliance.

Patient Education

• Listening to patients' concepts of normal bowel activity is important.
• Instituting a behavior modification program allows patients to become more aware of and responsive to normal urges to defecate.
• Emphasize the importance of a high-fiber diet.
• Emphasize adequate fluid intake.
• Emphasize regular exercise.
• For excellent patient education resources, visit eMedicine's Esophagus, Stomach, and Intestine Center. Also, see eMedicine's patient education articles Constipation in Adults and Constipation in Children.

MISCELLANEOUS

Section 9 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Medical/Legal Pitfalls

• Failure to discover an obstructing lesion of the colon (eg, tumor, volvulus) as the cause of constipation
• Failure to consider intestinal perforation in the patient who has been self-administering enemas at home
• Failure to treat an underlying systemic illness (eg, hypothyroidism)
• Failure to adequately hydrate or correct any underlying electrolyte imbalance

MULTIMEDIA

Section 10 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Media file 1:  Large amount of stool throughout the colon.
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Media type:  X-RAY

Media file 2:  Large stool mass in hepatic flexure of the colon.
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Media type:  X-RAY

Media file 3:  Colon distension secondary to fecal impaction.
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Media type:  X-RAY

Media file 4:  Pseudo-obstruction secondary to fecal impaction.
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Media type:  X-RAY

Media file 5:  Distended transverse colon.
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Media type:  CT

Media file 6:  Distended rectum.
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Media type:  CT

REFERENCES

Section 11 of 11

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

• Halligan S, Bartram CI. The radiological investigation of constipation. Clin Radiol. Jul 1995;50(7):429-35. [Medline].
• Harari D, Gurwitz JH, Avorn J, Bohn R, Minaker KL. How do older persons define constipation? Implications for therapeutic management. J Gen Intern Med. Jan 1997;12(1):63-6. [Medline].
• Johanson JF, Sonnenberg A, Koch TR. Clinical epidemiology of chronic constipation. J Clin Gastroenterol. Oct 1989;11(5):525-36. [Medline].
• Martin H, Slyk MP, Deymann S, Cornacchione MJ. Safety profile assessment of risperidone and olanzapine in long-term care patients with dementia. J Am Med Dir Assoc. Jul-Aug 2003;4(4):183-8. [Medline].
• Mezwa DG, Feczko PJ, Bosanko C. Radiologic evaluation of constipation and anorectal disorders. Radiol Clin North Am. Nov 1993;31(6):1375-93. [Medline].
• Rantis PC Jr, Vernava AM 3rd, Daniel GL, Longo WE. Chronic constipation--is the work-up worth the cost?. Dis Colon Rectum. Mar 1997;40(3):280-6. [Medline].
• Schiller LR. New and emerging treatment options for chronic constipation. Rev Gastroenterol Disord. 2004;4 Suppl 2:S43-51. [Medline].
• Shafik A. Constipation. Pathogenesis and management. Drugs. Apr 1993;45(4):528-40. [Medline].
• Sonnenberg A, Koch TR. Epidemiology of constipation in the United States. Dis Colon Rectum. Jan 1989;32(1):1-8. [Medline].
• Velio P, Bassotti G. Chronic idiopathic constipation: pathophysiology and treatment. J Clin Gastroenterol. Apr 1996;22(3):190-6. [Medline].

Article Last Updated: Aug 2, 2007