Defining Constipation: When to Call It Constipation
Constipation is defined as having fewer than three bowel movements per week, accompanied by symptoms such as hard stools, straining, or a sensation of incomplete evacuation. 1
Clinical Definition and Diagnostic Criteria
The standard clinical definition of constipation is based on the Rome criteria, which requires the presence of at least two of the following symptoms for at least 12 weeks in the previous 12 months (not necessarily consecutive):
- Straining during bowel movements
- Lumpy or hard stools
- Sensation of incomplete evacuation
- Sensation of anorectal blockage or obstruction
- Manual maneuvers to facilitate defecation
- Fewer than 3 bowel movements per week 1
It's important to note that constipation is subjective and involves both objective symptoms (stool characteristics and frequency) and patient perception (discomfort and ease of defecation).
Types of Constipation
Constipation can be categorized into several clinical subgroups:
- Normal Transit Constipation (NTC): Normal colonic transit time with symptoms of constipation
- Slow Transit Constipation (STC): Delayed colonic transit
- Defecatory Disorders: Impaired rectal evacuation due to inadequate rectal propulsive forces or increased resistance to evacuation 1
Assessment of Constipation
When evaluating constipation, consider:
- Stool frequency (less than 3 per week indicates constipation)
- Stool consistency (hard, lumpy stools)
- Difficulty with evacuation (straining, sensation of blockage)
- Duration of symptoms (occasional vs. chronic)
Risk Factors and Contributing Factors
Several factors can contribute to constipation:
- Medications (opioids, antacids, anticholinergics, antidepressants, antiemetics)
- Metabolic disorders (hypercalcemia, hypothyroidism, diabetes mellitus)
- Neurological conditions (Parkinson's disease, spinal cord lesions)
- Dietary factors (low fiber intake, inadequate fluid intake)
- Reduced physical activity
- Advanced age (prevalence increases in older adults) 1
Management Approach
For occasional constipation:
Preventive measures:
- Adequate fluid intake
- Dietary fiber intake
- Regular physical activity when feasible 1
First-line interventions:
- Stool softeners combined with stimulant laxatives (e.g., senna with docusate)
- Increase laxative dose when increasing opioid doses (if applicable) 1
For persistent constipation:
- Reassess for cause and severity
- Rule out impaction or obstruction
- Consider adding agents such as polyethylene glycol, lactulose, magnesium hydroxide, or bisacodyl 1
Special Considerations
Opioid-Induced Constipation
For patients on opioid therapy, prophylactic laxative therapy is recommended with a stimulant laxative plus stool softener. If constipation persists despite standard laxative therapy, methylnaltrexone may be considered 1.
Elderly Patients
Older adults are five times more prone to constipation than younger individuals due to polypharmacy, reduced mobility, decreased hydration, and diminished urge to defecate 1.
Common Pitfalls to Avoid
Focusing only on frequency: Remember that constipation involves multiple symptoms beyond just infrequent bowel movements.
Overlooking medications: Many medications can cause or worsen constipation.
Missing serious underlying causes: While most constipation is functional, it's important to rule out structural causes like colorectal cancer, especially in older adults or those with alarm symptoms.
Inadequate preventive measures: Prevention through adequate hydration, fiber intake, and physical activity is often underemphasized.
Failing to adjust laxative regimens: Laxative regimens often need adjustment based on response and should be titrated to achieve one non-forced bowel movement every 1-2 days 1.
By understanding the definition and proper assessment of constipation, healthcare providers can implement appropriate management strategies to improve patient outcomes and quality of life.