Constipation in Emergency Medicine Clinical Presentation

History is most relevant regarding the etiology of constipation. During the history, clinicians should ask about current medications (including over-the-counter, herbal agents, and prescription medications), history of previous colonoscopy, and any other medical problems. The clinician should also check for the presence of abdominal pain as a primary symptom (if present, irritable bowel syndrome with constipation [IBS-C] should be considered). Understanding the type and degree of disability caused by the symptoms is also 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
• Use of manual maneuvers to facilitate defecation

The patient may be totally asymptomatic or complain of the following:

• Abdominal bloating
• Pain on defecation
• Rectal bleeding
• Spurious diarrhea
• Low back pain

The onset of symptoms is also very important, as intestinal obstruction can present as acute constipation.

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
• Inability to pass flatus
• Vomiting
• Unexplained weight loss

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 and/or pelvic examination
• Local anorectal lesions, which can cause or contribute to constipation (eg, anal fissures, fistulae, strictures, cancer, thrombosed hemorrhoids)
• Visible intussusception during straining

During the rectal examination, the patient should be assessed for the following:

• Perianal excoriation
• Skin tags/hemorrhoids
• Anal fissure
• Anocutaneous reflex
• Prolapse 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 a rectocele (an outpouching usually present in the anterior rectal wall)
• Presence of gross blood or occult bleeding by checking the stool guaiac
• Presence of fecal impactionPseudo-obstruction secondary to fecal impaction.
• 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.

The etiology of constipation is usually multifactorial, but it can be divided into 2 main groups: primary constipation and secondary constipation.

Primary constipation

Primary (idiopathic, functional) constipation can generally be classified into 3 categories:

• Normal-transit constipation (NTC) is the most common subtype of primary constipation. Although the stool is passing through the colon at a normal rate, patients perceive difficulty in evacuating their bowels. Patients in this category sometimes meet the criteria for IBS-C. The primary difference between chronic constipation and IBS-C is the prominence of abdominal pain or discomfort in IBS. Patients with NTC usually have a normal physical examination.
• Slow-transit constipation (STC) is characterized by infrequent bowel movements, decreased urgency, or straining to defecate. It occurs more commonly in female patients. Patients with STC have impaired phasic colonic motor activity. These patients may demonstrate mild abdominal distention or palpable stool in the sigmoid colon.
• Pelvic floor dysfunction (ie, pelvic floor dyssynergia) is characterized by dysfunction of the pelvic floor or anal sphincter. Patients often report prolonged or excessive straining, feeling of incomplete evacuation, or the use of perineal or vaginal pressure during defecation to allow the passage of stool or report digital evacuation of stool.

Secondary constipation

Secondary constipation: Several medical conditions and medications may lead to chronic constipation.

• Diet and exercise - Low-fiber content, decreased fluid intake, decreased exercise, and ignoring the urge to defecate
• Structural - Anal fissures, thrombosed hemorrhoids, colonic strictures, obstructing tumors, volvulus, and idiopathic megarectum
• Endocrinopathic and metabolic -Hypercalcemia, hyperparathyroidism, hypokalemia, hypothyroidism, pregnancy, and diabetes mellitus (Constipation is the most common gastrointestinal problem affecting the diabetic population.)
• 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
• Toxicologic -Lead poisoning
• Psychologic - Depression, anxiety, somatization, and eating disorders