Constipation Explained: Causes, Symptoms, and Prevention Tips

Constipation is defined as fewer than 3 bowel movements per week, with stools that are hard, dry, difficult to pass, or accompanied by a sense of incomplete evacuation. It affects ~16% of adults and 33% of those >60.

Primary Causes

• Dietary: Low fiber (<25 g/day), inadequate fluids (<2 L/day), low fruit/vegetable intake.
• Lifestyle: Physical inactivity, ignoring defecation urge, travel/schedule disruption.
• Medications: Opioids, anticholinergics, calcium channel blockers, iron, antacids (Al/Ca), antidepressants (TCAs), antipsychotics, GLP-1 agonists.
• Medical Conditions: Diabetes (autonomic neuropathy), hypothyroidism, hypercalcemia, Parkinson's, MS, IBS-C, Hirschsprung's, colorectal cancer.
• Pregnancy: Progesterone ↓ motility + uterine compression.
• Aging: Reduced colonic motility, polypharmacy, comorbidities.

Red Flags (Require Prompt Evaluation)

• Onset after age 50 (new symptom)
• Blood in stool (melena or hematochezia)
• Unintentional weight loss
• Anemia (iron deficiency)
• Family history of colorectal cancer/IBD
• Nocturnal diarrhea or incontinence
• Failure to respond to adequate fiber/fluids/laxatives

Prevention & First-Line Management

1. Fiber: 25–35 g/day (gradual increase). Soluble (oats, psyllium, fruit) + insoluble (whole grains, veg).
2. Fluids: 2–3 L/day water/non-caffeinated.
3. Exercise: 30 min/day moderate activity stimulates colonic motility.
4. Toilet Habits: Regular time (post-breakfast), don't ignore urge, proper posture (footstool for knees > hips).
5. Osmotic Laxatives (if needed): PEG 3350 (MiraLAX) 17 g daily—safe long-term. Avoid chronic stimulant laxatives (senna, bisacodyl).

When to See a Doctor

If constipation is new, persistent >3 weeks despite lifestyle changes, or accompanied by red flags. Colonoscopy may be indicated for age-appropriate screening or alarm features.