Constipation (2024)

How does constipation happen?

Constipation happens because your colon (large intestine) absorbs too much water from your poop. This dries out your poop, making it hard in consistency and difficult to push out of your body.

To back up a bit, as food normally moves through your digestive tract, your intestines gradually absorb the nutrients. The partially digested food (waste) that passes from your small intestine to your large intestine becomes your poop. Your colon absorbs water from this waste, which makes it more solid. If you have constipation, food may move too slowly through your digestive tract. This gives your colon more time — too much time — to absorb water from the waste. The stool becomes dry, hard and difficult to push out.

What causes constipation?

There are many causes of constipation, including lifestyle factors, medications and medical conditions.

Lifestyle factors

Common lifestyle causes of constipation include:

• Not eating enough fiber.
• Not drinking enough water (dehydration).
• Not getting enough exercise.
• Changes in your regular routine, such as traveling or eating, or going to bed at different times.
• Consuming large amounts of milk or cheese.
• Stress.
• Resisting the urge to have a bowel movement.

Medications

Medications that can cause constipation include:

• Strong pain medicines, like narcotics containing codeine, oxycodone (Oxycontin®) and hydromorphone (Dilaudid®).
• Nonsteroidal anti-inflammatory drugs (NSAIDs), like ibuprofen (Advil®, Motrin®) and naproxen (Aleve®).
• Antidepressants, including selective serotonin reuptake inhibitors (like fluoxetine [Prozac®]) or tricyclic antidepressants (like amitriptyline [Elavil®]).
• Antacids containing calcium or aluminum, such as Tums®.
• Iron pills.
• Allergy medications, such as antihistamines (like diphenhydramine [Benadryl®]).
• Certain blood pressure medicines, including calcium channel blockers (like verapamil [Calan SR®], diltiazem [Cardizem®] and nifedipine [Procardia®]) and beta-blockers (like atenolol [Tenormin®]).
• Psychiatric medications, like clozapine (Clozaril®) and olanzapine (Zyprexa®).
• Antiseizure medications, such as phenytoin and gabapentin.
• Antinausea medications, like ondansetron (Zofran®).

Many drugs can cause constipation. Ask your healthcare provider or pharmacist if you have any questions or concerns.

Medical conditions

Medical and health conditions that can cause constipation include:

• Endocrine conditions, like underactive thyroid gland (hypothyroidism), diabetes, uremia and hypercalcemia.
• Colorectal cancer.
• Irritable bowel syndrome (IBS).
• Diverticulitis.
• Outlet dysfunction constipation. This is a defect in the coordination of your pelvic floor muscles. These muscles support the organs within your pelvis and lower abdomen. They’re needed to help release poop.
• Obstructed defecation syndrome. Complex or unexplained causes may be preventing you from pooping normally.
• Intestinal pseudo-obstruction. Sometimes, the motor system in your colon can become temporarily paralyzed (as in paralytic ileus or Ogilvie syndrome).
• Neurologic disorders, including spinal cord injury, multiple sclerosis, Parkinson’s disease and stroke.
• Lazy bowel syndrome. This is when your colon contracts poorly and retains poop.
• Intestinal obstruction.
• Structural defects in your digestive tract (like fistula, colonic atresia, volvulus, intussusception, imperforate anus or malrotation).
• Multiple organ diseases, such as amyloidosis, lupus and scleroderma.
• Pregnancy.

What are the symptoms of constipation?

Constipation symptoms include:

• You have fewer than three bowel movements a week.
• Your stools are dry, hard and/or lumpy.
• Your stools are difficult or painful to pass.
• You have a stomachache or cramps.
• You feel bloated and nauseated.
• You feel that you haven’t completely emptied your bowels after a movement.

What are the risk factors for constipation?

People of all ages can have an occasional bout of constipation. But certain risk factors make people more likely to become consistently constipated (“chronic constipation”). These factors include:

• Age. People older than 65 are often less active, have a slower metabolism and have less muscle contraction strength along their digestive tract than when they were younger.
• Being assigned female at birth, especially constipation during pregnancy and after childbirth. Changes in your hormones may make you more prone to constipation. The fetus inside your uterus may squish your intestines, slowing down the passage of stool.
• Not eating enough high-fiber foods. Fiber keeps food moving through your digestive system.
• Taking certain medications.
• Having certain neurological (diseases of the brain and spinal cord) and digestive diseases.

Can constipation cause internal damage or lead to other health problems?

There are a few complications that could happen if you don’t have soft, regular bowel movements. Some complications include:

• Swollen, inflamed veins in your rectum (hemorrhoids).
• Tears in the lining of your anus from hardened stool trying to pass through (anal fissures).
• An infection in the pouches (diverticula) that sometimes form off your colon wall from stool that’s become trapped and infected (diverticulitis).
• A pile-up of too much poop in your rectum and anus (fecal impaction).
• Damage to your pelvic floor muscles from straining to move your bowels. These muscles help control your bladder, among other things. Too much straining for too long may cause urine to leak from your bladder (stress urinary incontinence).

Can constipation cause toxins to build up in my body and make me sick?

This usually isn’t the case. Although your colon holds on to stool longer when you’re constipated and you may feel uncomfortable, it’s an expandable container for your waste. It takes a severe illness in your colon for the walls to leak toxins into your body (toxic megacolon).