Introduction
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
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
More on Constipation |
 Overview: Constipation |
| Differential Diagnoses & Workup: Constipation |
| Treatment & Medication: Constipation |
| Follow-up: Constipation |
| Multimedia: Constipation |
| References |
| Next Page » |
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].
Further Reading
Keywords
hard stool, impaction, defecation, bowel movement, straining, colonic functional disorder, anorectal functional disorder, sensation of incomplete evacuation, fewer bowel movements, colonic inertia, functional constipation, abdominal colectomy, ileorectal anastomosis, abdominal bloating, pain on defecation, rectal bleeding, low back pain, digital extraction, tenesmus, enema retention, anal fissures, anal fistulae, anal strictures, anal cancer, thrombosed hemorrhoids, intussusception, pelvic outlet dysfunction, irritable bowel syndrome, hypercalcemia, hypokalemia, hypothyroidism, diabetes mellitus, stroke, Parkinson disease, multiple sclerosis, spinal cord lesion, Chagas disease, familial dysautonomia, scleroderma, amyloidosis, mixed connective-tissue disease, depression, idiopathic megacolon, idiopathic megarectum, idiopathic slow transit constipation, chronic intestinal obstruction, rectal outlet obstruction, anismus, solitary rectal ulcer, descending perineum, rectocele, weak pelvic floor, Hirschsprung disease
