What causes constipation?

Your colon’s main job is to absorb water from residual food as it’s passing through your digestive system. It then creates stool (waste).

The colon’s muscles eventually propel the waste out through the rectum to be eliminated. If stool remains in the colon too long, it can become hard and difficult to pass.

Poor diet frequently causes constipation. Dietary fiber and adequate water intake are necessary to help keep stools soft.

Fiber-rich foods are generally made from plants. Fiber comes in soluble and insoluble forms. The soluble fiber can dissolve in water and creates a soft, gel-like material as it passes through the digestive system.

Insoluble fiber retains most of its structure as it goes through the digestive system. Both forms of fiber join with stool, increasing its weight and size while also softening it. This makes it easier to pass through the rectum.

Stress, changes in routine, and conditions that slow muscle contractions of the colon or delay your urge to go may also lead to constipation.

Common causes of constipation include:

  • low-fiber diet, particularly diets high in meat, milk, or cheese
  • dehydration
  • lack of exercise
  • delaying the impulse to have a bowel movement
  • travel or other changes in routine
  • certain medications, such as high calcium antacids and pain medications
  • pregnancy

Underlying medical problems

The following are some underlying medical problems that can bring on constipation:

  • certain diseases, such as stroke, Parkinson’s disease, and diabetes
  • problems with the colon or rectum, including intestinal obstruction, irritable bowel syndrome (IBS), or diverticulosis
  • overuse or misuse of laxatives (medications to loosen stools)
  • hormonal problems, including an underactive thyroid gland

What are the signs of constipation?

Each person’s definition of normal bowel movements may be different. Some individuals go three times a day, while others go three times a week.

However, you may be constipated if you experience the following symptoms:

  • fewer than three bowel movements a week
  • passing hard, dry stools
  • straining or pain during bowel movements
  • a feeling of fullness, even after having a bowel movement
  • experiencing a rectal blockage

Who is at risk for constipation?

Eating a poor diet and not exercising are major risk factors for constipation. You may also be at greater risk if you’re:

  • Age 65 or older. Older adults tend to be less physically active, have underlying diseases, and eat poorer diets.
  • Confined to bed. Those who have certain medical conditions, such as spinal cord injuries, often have difficulty with bowel movements.
  • A woman or child. Women have more frequent episodes of constipation than men, and children are affected more often than adults.
  • Pregnant. Hormonal changes and pressure on your intestines from your growing baby can lead to constipation.

How is constipation diagnosed?

Many people affected by constipation choose to self-treat by changing their diets, increasing exercise, or using over-the-counter laxatives.

However, laxatives shouldn’t be used for more than two weeks without consulting a physician. Your body can become dependent on them for colon function.

You should talk to your primary care provider if:

  • you’ve had constipation for more than three weeks
  • you have blood in your stool
  • you have abdominal pain
  • you’re experiencing pain during bowel movements
  • you’re losing weight
  • you have sudden changes in your bowel movements

Your doctor will ask questions about your symptoms, medical history, and any medications or underlying conditions.

A physical examination may include a rectal exam and blood tests to check your blood count, electrolytes, and thyroid function.

In severe cases, additional tests may be required to identify the cause of your symptoms. Tests may include the following:

Marker study

A marker study, also called a colorectal transit study, is used to test how food is moving through your colon. For this test, you’ll swallow a pill that contains tiny markers that will show up on an X-ray.

Numerous abdominal X-rays will be taken over the next few days so the doctor can visualize how the food is moving through your colon and how well your intestinal muscles are working.

You may also be asked to eat a diet high in fiber during the test.

Anorectal manometry

An anorectal manometry is a test used to evaluate anal sphincter muscle function. For this test, your doctor will insert a thin tube with a balloon tip into your anus.

When the tube is inside, the doctor will inflate the balloon and slowly pull it out. This test allows them to measure your anal sphincter’s muscle strength and see if your muscles are contracting properly.

Barium enema X-ray

A barium enema X-ray is a type of test used to examine the colon. For this test, you’ll drink a special liquid the night before the test to clean out the bowel.

The actual test involves the insertion of a dye called barium into your rectum, using a lubricated tube. The barium highlights the rectum and colon area, allowing the doctor to better view them on an X-ray.


A colonoscopy is another type of test doctors use to examine the colon. In this test, your doctor will examine your colon using a tube that’s outfitted with a camera and light source (colonoscope).

A sedative and pain medication is often given, so you’ll likely not even remember the examination and should feel no pain.

To prepare for this test, you’ll be on a liquid-only diet for 1 to 3 days, and you may have to take a laxative or enema the night before the test to clean out the bowel.

How to treat and prevent constipation

Changing your diet and increasing your physical activity level are the easiest and fastest ways to treat and prevent constipation. Try the following techniques as well:

  • Every day, drink 1 1/2 to 2 quarts of unsweetened, decaffeinated fluids, like water, to hydrate the body.
  • Limit consumption of alcohol and caffeinated drinks, which cause dehydration.
  • Add fiber-rich foods to your diet, such as raw fruits and vegetables, whole grains, beans, prunes, or bran cereal. Your daily intake of fiber should be between 20 and 35 grams.
  • Cut down on low-fiber foods, such as meat, milk, cheese, and processed foods.
  • Aim for about 150 minutes of moderate exercise every week, with a goal of 30 minutes per day at least five times per week. Try walking, swimming, or biking.
  • If you feel the urge to have a bowel movement, don’t delay. The longer you wait, the harder your stool can become.
  • Add fiber supplements to your diet if needed. Just remember to drink plenty of fluids because fluids help fiber work more efficiently.
  • Use laxatives sparingly. Your doctor may prescribe laxatives or enemas for a short period of time to help soften your stools. Never use laxatives for more than two weeks without talking to your doctor. Your body can become dependent on them for proper colon function.
  • Consider adding probiotics to your diet, like those found in yogurt and kefir with live active cultures. Studies Trusted Source have shown that this dietary change can be helpful for those with chronic constipation.

If you still have trouble with constipation, your doctor may prescribe medications to help.

According to a study Trusted Source, linaclotide (Linzess) is recommended for people with IBS-related constipation.

These medications work by increasing the secretions in your intestines, making the stool easier to pass.

Your doctor may also advise that you stop taking certain medications that may cause constipation.

More severe colon or rectal problems may require manual procedures to clear the colon of impacted stool, therapy to retrain slow muscles, or surgery to remove the problem part of your colon.

Your digestion highway

The digestive tract extends from your mouth to your rectum. Some of the main organs involved in digestion are the:

  • stomach
  • small intestine
  • large intestine, where stool ultimately exits via the rectum

Along each point of the gastrointestinal tract, nutrients are absorbed and the wastes from food breakdown are ultimately released from the body.

Special motions including churning in the stomach and peristalsis (a rhythmic movement) in the intestines help to propel food material forward through the digestive tract.

The softer and bulkier the stool is, the more likely it is to activate the movements of the intestines and move forward. When it’s time for you to go to the bathroom, muscles in your pelvic floor work together to help push stool out of the rectum.

What are the treatments for constipation?

Constipation treatments can range from lifestyle to medication treatments. If you have an obstruction or scarring that is blocking the movement of your stool, you may require surgery.

Some at-home, self-care measures you can use to reduce the incidence of constipation include:

  • Drinking plenty of water to where your urine should be pale yellow in color.
  • Eating at least 25 grams of fiber a day through sources such as vegetables, whole grains, and fruits.
  • Engaging in regular physical activity, such as walking, riding a bicycle, or dancing. These physical activity elements can mimic the natural movement of the stool and help stool move more quickly.
  • Talking to your doctor about medications you may be taking that affect constipation. However, you shouldn’t stop taking your medicines without talking to your doctor first.

There are also over-the-counter (OTC) medications that can ideally reduce constipation, such as fiber supplements.

What does constipation feel like when pregnant?

Pregnant women experience constipation at a higher rate than the general population. An estimated 11 to 38 percent Trusted Source of pregnant women have problems with constipation.

Some of the factors that make it more likely pregnant women will have constipation include:

  • increased progesterone levels and reduced hormones called motilin that slow intestinal movement
  • increased water absorption in the intestines that causes stool to dry out
  • increased calcium and iron supplements that can increase constipation risk
  • enlarged uterus that presses on the intestines, slowing their movement
  • decreased physical activity

Constipation may be difficult to recognize initially if you’re pregnant because you may be uncertain your symptoms are related to pregnancy. Examples could include bloating or feelings of abdominal fullness and pressure.

When you’re pregnant, you can’t take the same medications you did when you weren’t expecting, due to concerns the medicines could affect the baby.

Also, there isn’t a lot of data about the safety of using laxatives to promote bowel movements during pregnancy.

However, some treatments that do not seem to be associated with adverse side effects include:

  • bulk-forming agents (although these can cause gas, cramping, and bloating in some pregnant women)
  • lubricant laxatives, such as mineral oil
  • stool softeners, such as docusate sodium (Colace)

Sometimes laxatives can lead to electrolyte imbalances that could cause you to feel ill and potentially affect your baby.

For this reason, it’s important that if you’re pregnant you take these medications for a short time and try lifestyle techniques, such as more fiber, increased water intake, and more physical activity (if tolerated).

What causes constipation?

Constipation can result from several underlying reasons. These can include:

  • aging
  • diabetes
  • dietary changes, such as lower fiber or not drinking enough fluids
  • history of colon surgery
  • history of gastrointestinal disorders, such as irritable bowel syndrome
  • history of pelvic floor disorders
  • intestinal obstructions
  • pregnancy

It can also result from taking certain medications, such as:

  • aluminum- and calcium-containing antacids
  • anticonvulsants
  • calcium channel blockers
  • diuretics
  • iron supplements
  • narcotic pain medications
  • medicines used to treat Parkinson’s disease

Sometimes, the movement of the colon slows for no known reason and constipation results.

The takeaway

Whether temporary or chronic, constipation can be an unpleasant occurrence whose symptoms don’t always happen where and when you think they will.

Fortunately, most instances of constipation can resolve with at-home, self-care measures. If your symptoms don’t resolve or you experience pain and bleeding, call a doctor.

If you have fewer than three bowel movements a week combined with difficulty with your bowel movements or other discomfort, it may be worthwhile to talk to a doctor.