Constipation
Constipation is infrequent, difficult, or incomplete defecation that is secondary to an identifiable cause, most often a medication, or functional once secondary causes are excluded. Diagnosis rests on alarm-feature screening and Rome IV criteria for the functional subtype, and treatment proceeds stepwise from fiber and osmotic laxatives through secretagogues, prokinetics, biofeedback, or peripheral opioid antagonists.
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What this article covers
- Overview
Definition: infrequent, difficult, or incomplete defecation, acute or chronic, secondary (an identifiable cause) or functional (idiopathic, once secondary causes are excluded).
- Epidemiology
General population burden: affects roughly one in five adults, a frequent reason for gastrointestinal consultation.
- Risk factors
Opioid use: the single most important reversible drug cause; opioids directly reduce gastrointestinal motility.
- Pathophysiology
Secondary constipation: an identifiable structural, metabolic, neurologic, or pharmacologic process slows transit or impairs evacuation; medications are the leading mechanism, most often through…
- Clinical features
Core symptoms: infrequent defecation, difficult or straining defecation, and a sensation of incomplete or blocked evacuation, alone or in combination.
- Differential diagnosis
Colorectal cancer: new constipation with weight loss, hematochezia, iron deficiency anemia, or age over 50 without prior screening; excluded by colonoscopy.
- Diagnosis
Functional constipation is a clinical diagnosis by Rome IV criteria once secondary causes are excluded: the criteria above (at least two of six features on 25% or more of defecations, over three…
- Management
Start with lifestyle and dietary modification for every patient: increase dietary or supplemental fiber to 25 to 30 g per day, increase fluids, and increase activity; soluble fiber (psyllium 1…
- Complications
Fecal impaction with overflow incontinence: longstanding untreated constipation can progress to a hard, immovable fecal mass with paradoxical loose overflow stool, and to fecal incontinence.
- Prognosis
Functional constipation is generally chronic but manageable: most patients improve with stepwise therapy, though symptoms often recur if therapy is stopped.
- Prevention
Colon cancer screening prevents malignancy-related constipation: average-risk adults begin screening colonoscopy at age 45; new constipation with no prior screening after age 50 requires colonoscopy at presentation.
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Related articles
- Irritable bowel syndrome (IBS)
Irritable bowel syndrome is a functional disorder of gut-brain interaction diagnosed clinically by Rome IV criteria, recurrent abdominal pain related to defecation, stool frequency, or stool form, without alarm features. Management is subtyped by stool pattern, with fiber and dietary change first, then IBS-C secretagogues or IBS-D antidiarrheals and antibiotics, and low-dose tricyclics or antispasmodics for pain.
- Fecal incontinence
Fecal incontinence is the recurrent, involuntary passage of fecal material for at least three months, most often from a combination of obstetric or surgical sphincter injury, altered stool consistency, and impaired rectal sensation. Diagnosis rests on history and digital rectal exam followed by anorectal manometry and anal endosonography, and treatment moves stepwise from correcting stool consistency and reversible causes to pelvic floor therapy, biofeedback, and, for refractory or structural disease, bulking agents, sacral nerve stimulation, or sphincteroplasty.