Constipation occurs when stool moves slowly through the colon, due to low fiber, dehydration, inactivity, or certain medicines.
Causes
Stool moves slowly, so the colon absorbs more water and the stool hardens.
Common triggers
- Low fiber.
- Dehydration.
- Inactivity.
- Ignoring the urge.
- Medicines (opioids, iron, antacids).
- IBS and hypothyroidism.
- Pregnancy.
Definition
Fewer than 3 bowel movements a week.
Fix
25 to 38 g of fiber a day, water and exercise.
See a doctor
If it lasts over 3 weeks or has blood.
Definition and numbers
Constipation is generally defined as fewer than 3 bowel movements per week, or hard stools, straining or incomplete emptying. It affects roughly 16 percent of adults worldwide, with higher rates in women and older adults, according to a 2011 review.
- Low fiber, low fluid intake and inactivity slow stool.
- Medicines linked to constipation include opioids, iron supplements, anticholinergics, calcium channel blockers and some antidepressants.
- Hypothyroidism, diabetes, irritable bowel syndrome, pelvic floor dysfunction and neurological disease contribute.
- Ignoring the urge to defecate can worsen it.
Fix and when to see a doctor
Adults are advised to eat 25 to 34 g of fiber daily, drink water and walk. Fiber supplements (psyllium), osmotic laxatives (polyethylene glycol) and stool softeners are options. Seek care for blood in stool, unexplained weight loss, severe pain, new constipation after age 50, or constipation lasting over 3 weeks, because colorectal conditions need to be excluded.
Definition and numbers
Constipation is usually defined as fewer than three bowel movements a week, with hard stools or straining. The NIH estimates it affects about 16 percent of US adults and about 33 percent of those over 60. Causes include low fiber, low fluid, inactivity, ignoring the urge, medicines (opioids, iron, some antidepressants), hypothyroidism and pregnancy.
Fix and when to see a doctor
Adults should aim for 25 to 38 g of fiber a day, drink fluids and exercise. Osmotic laxatives such as polyethylene glycol are options, and stimulants should not be used long term without advice. See a doctor for blood in stool, unexplained weight loss, severe pain or new constipation after age 45.
Mechanisms in the colon
The colon absorbs water and moves stool by contractions; slow transit allows more water to be absorbed, hardening stool. Pelvic floor dysfunction (dyssynergic defecation) causes difficulty expelling stool in up to half of people with chronic constipation. Opioids slow motility by acting on gut receptors.
Treatment options
Fiber supplements like psyllium (5 to 10 g daily) soften stools. Polyethylene glycol, lactulose and senna are common medicines. Prescription options include linaclotide, lubiprostone and prucalopride. Biofeedback therapy helps pelvic floor problems, with success rates of 70 percent in trials. Regular toilet time after meals and a footstool for squat posture help.
Based on data from the American College of Gastroenterology and the NIDDK
