Constipation is formally defined by infrequent bowel movements, difficulty passing stool, or a feeling of incomplete emptying. In clinical practice, passing fewer than three stools per week is a common threshold for concern.
Normal bowel function relies on coordinated movements of the colon. The colon absorbs water and electrolytes from indigestible food matter, turning liquid chyme into formed stool. Peristalsis—wave-like muscle contractions—then propels this waste toward the rectum. When stool remains in the colon too long, excessive water is reabsorbed, resulting in hard, dry feces that are difficult to expel.
Constipation is broadly categorized into primary and secondary types. Primary constipation involves intrinsic defects within the colon or anorectum, whereas secondary constipation stems from external factors like systemic diseases, medications, or lifestyle habits.
Patients experiencing constipation present with subjective complaints and observable signs that require careful nursing evaluation. A thorough history must capture bowel habits, stool consistency using the Bristol Stool Chart, dietary patterns, fluid intake, and medication history.
Pharmacological treatment depends on the underlying cause and severity of constipation. Nurses must understand the mechanisms of various laxative classes to monitor effectiveness and prevent adverse effects.
| Laxative Class | Mechanism of Action | Example |
|---|---|---|
| Bulk-forming | Absorbs water to increase stool mass | Psyllium |
| Osmotic | Draws water into the intestinal lumen | Lactulose |
| Stimulant | Irritates bowel mucosa to increase peristalsis | Bisacodyl |
| Stool Softener | Lowers surface tension to allow water entry | Docusate sodium |
Non-pharmacological strategies form the foundation of nursing care for constipation. Dietary modifications should focus on increasing fiber gradually through fruits, vegetables, and whole grains, paired with adequate daily fluid intake.
Encouraging physical activity stimulates colonic motility. Nurses should also assist patients in establishing regular bowel routines, such as attempting defecation 15 to 30 minutes after meals when the gastrocolic reflex is naturally strongest. Proper positioning, using a footstool to elevate the knees during defecation, straightens the anorectal angle and reduces straining.
Unresolved constipation can lead to significant clinical complications, particularly in vulnerable populations such as older adults or immobilized patients.