Definition of Constipation
Constipation is defined as the slow movement of faeces through the large intestine, resulting in infrequent bowel movements and the passage of dry, hard stools, which can significantly impact quality of life. 1
Clinical Definition Based on Rome III Criteria
Constipation is diagnosed when a patient presents with at least two of the following symptoms for at least 12 weeks in the previous 12 months (not necessarily consecutively):
- Straining during bowel movements 1
- Lumpy or hard stool 1
- Sensation of incomplete evacuation 1
- Sensation of anorectal blockage or obstruction 1
- Manual evacuation procedures to remove stool 1
- Fewer than 3 bowel movements per week 1
Subjective Experience and Perception
The experience of constipation is highly subjective and involves two key aspects:
- Measurable objective symptoms, including stool characteristics and frequency of defecation 1
- Patient perception, level of discomfort, and ease of defecation 1
Types of Constipation
Constipation can be classified into different types:
- Chronic (functional) constipation - persistent symptoms meeting Rome criteria 1, 2
- Occasional constipation - intermittent or occasional symptomatic alterations in bowel habit that may last for a few days or weeks 3
- Opioid-induced constipation - defined in Rome IV criteria as "constipation triggered or worsened by opioid analgesics" 1
Pathophysiological Mechanism
Normal bowel function involves:
- Colonic absorption of fluids and transport of waste through peristalsis (primarily mediated by serotonin) 1, 4
- Active reabsorption of sodium through transport channels and water through osmosis 1
- Rectal distension leading to the urge to defecate 1, 2
- Average colonic transit time of 20-72 hours 1
Constipation represents a disruption of these normal mechanisms due to:
- Primary causes (colonic or anorectal dysfunction) 1, 2
- Secondary causes (disease- or medication-related) 1, 4
- Contributing factors including disrupted motility, excessive dryness of fecal content, diminished perception of rectal distension, and dysfunction of the rectal sphincter 1, 2
Clinical Significance
Constipation is:
- A symptom, not a disease 1
- A common problem affecting approximately 15% of the population 3
- Often self-diagnosed and self-managed 3, 5
- A significant source of morbidity and distress 1
- Associated with complications including hemorrhoids, anal fissures, bowel obstruction, and urinary retention if left untreated 1
Important Diagnostic Considerations
- Constipation should be distinguished from other bowel disorders through careful assessment 5
- Alarm signs warrant further investigation to rule out secondary causes 5
- Diagnostic testing may include anorectal manometry to assess outlet function in refractory cases 5, 2
- Dyssynergic defecation, a functional defecation disorder, is present in approximately two-thirds of adult patients with constipation 2