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Definition & Facts

What is Constipation?

Constipation is a condition in which you typically have:

  • fewer than three bowel movements a week
  • bowel movements with stools that are hard, dry, and small, making them painful or difficult to pass

Some people think they are constipated if they don’t have a bowel movement every day. However, people can have different bowel movement patterns. Some people may have three bowel movements a day. Other people may only have three bowel movements a week.

Constipation most often lasts for only a short time and is not dangerous. You can take steps to prevent or relieve constipation.

How common is constipation?

Constipation is one of the most common gastrointestinal (GI) problems, affecting about 42 million people in the United States.1

Who is more likely to become constipated?

Constipation is common among all ages and populations in the United States, yet certain people are more likely to become constipated, including

  • women, especially during pregnancy or after giving birth
  • older adults
  • non-Caucasians
  • people with lower incomes
  • people who just had surgery
  • people taking medicines to treat depression or to relieve pain from things such as a broken bone, a pulled tooth, or back pain
Young pregnant woman looking into the refrigerator

What are the complications of constipation?

Chronic, or long-lasting, constipation can lead to health problems such as hemorrhoids, anal fissures, rectal prolapse, or fecal impaction.


Hemorrhoids are swollen and inflamed veins around your anus or in your lower rectum. You can develop hemorrhoids if you strain to have a bowel movement. If you have hemorrhoids, you may have bleeding in your rectum. You have bleeding in the rectum when you see bright red blood in your stool, on toilet paper, or in the toilet after a bowel movement.

Anal fissures

Anal fissures are small tears in your anus that may cause itching, pain, or bleeding.

Rectal prolapse

Rectal prolapse happens when your rectum slips so that it sticks out of your anus. Rectal prolapse can happen if you strain during bowel movements, among other reasons. Rectal prolapse may cause mucus to leak from your anus. Rectal prolapse is most common in older adults with a history of constipation, and is also more common in women than men, especially postmenopausal women.2

Fecal impaction

Fecal impaction happens when hard stool packs your intestine and rectum so tightly that the normal pushing action of your colon is not enough to push the stool out. Fecal impaction occurs most often in children and older adults.


Symptoms & Causes

What are the symptoms of constipation?

The most common symptoms of constipation are

  • fewer-than-normal bowel movements
  • stool that is difficult or painful to pass
  • pain or bloating in your abdomen

What causes constipation?

Constipation can happen for many reasons, and constipation may have more than one cause at a time. Among the most common causes of constipation are

  • slow movement of stool through the colon
  • delayed emptying of the colon from pelvic disorders, especially in women
  • a form of irritable bowel syndrome (IBS) that has symptoms of both IBS and constipation, also called IBS with constipation, or IBS-C.

Constipation may become worse because of the following factors:

Diets low in fiber

Fiber helps stool stay soft. Drink liquids to help fiber keep stool soft.

Older adults commonly have constipation because of limited dietary fiber, lack of physical activity, and medications.

Lack of physical activity

If you don’t exercise or move around regularly you may get constipated. For example, people may be less active because they

  • have other health problems
  • sit all day and don’t exercise regularly
  • have to stay in bed most of the time because of an illness or accident


Some medicines that doctors prescribe to treat other health problems can cause constipation. Medicines that can cause constipation include

  • antacids—used to neutralize stomach acid—that contain aluminum and calcium
  • anticholinergics—used to treat muscle spasms in the intestines
  • anticonvulsants—used to decrease abnormal electrical activity in the brain to prevent seizures
  • antispasmodics—used to reduce muscle spasms in the intestines
  • calcium channel blockers—used to treat high blood pressure and heart disease
  • diuretics—used to help the kidneys remove fluid from the blood
  • iron supplements—used to build up higher iron levels in the blood
  • medicines used to treat Parkinson’s disease
  • narcotics—used to treat severe pain
  • some medicines used to treat depression

Life changes or daily routine changes

Constipation can happen when your life or daily routine changes. For example, your bowel movements can change

  • when you travel
  • if you become pregnant
  • as you get older

Ignoring the urge to have a bowel movement

If you ignore the urge to have a bowel movement, over time, you may stop feeling the need to have one. You may delay having a bowel movement because you do not want to use toilets outside of your home, do not have access to a toilet, or may feel you are too busy. This habit can lead to constipation.

Certain health problems

Some health problems can make stool move more slowly through your colon, rectum, or anus, causing constipation. These health problems include

  • disorders that affect your brain and spine, such as Parkinson’s disease
  • spinal cord or brain injuries
  • diabetes
  • hypothyroidism

Gastrointestinal (GI) tract problems

Problems in your GI tract that compress or narrow your colon and rectum can cause constipation. These problems include

Functional GI disorders

Functional GI disorders happen when your GI tract behaves in an abnormal way, yet without evidence of damage due to a disease. For example, IBS is a common functional GI disorder, and many people with IBS can have IBS with constipation.


How do doctors diagnose constipation?

Doctors diagnose constipation by

  • taking a medical history
  • performing a physical exam
  • performing diagnostic tests, such as a blood test

Medical history

The medical history will include questions about your constipation, such as

  • how often you have a bowel movement
  • how long you’ve had symptoms
  • what your stools look like and whether you have blood in your stool
  • your eating habits
  • your level of physical activity
  • the medicines you take
A doctor taking the medical history of a patient at a desk.
To find out why you have constipation, your doctor will take your medical history.

Physical exam

The physical exam may include a digital rectal exam. During a digital rectal exam, your doctor will have you bend over a table or lie on your side while holding your knees close to your chest. After putting on a glove, the doctor slides a lubricated finger into your anus to check for tenderness, blockage, or blood, and will ask you to squeeze your anal muscles.

Diagnostic tests

The tests your doctor may order for constipation depend on

  • how long you’ve been constipated
  • how severe your constipation is
  • your age
  • whether you’ve had blood in your stool, recent changes in your bowel movement pattern, or weight loss

What tests do doctors use to diagnose constipation?

A doctor may use one or more of the following tests to diagnose constipation.

Blood test

A health care professional may take a blood sample from you to test for certain conditions that can cause constipation, such as anemia or hypothyroidism.

Flexible sigmoidoscopy or colonoscopy

Although the tests are similar, doctors use a colonoscopy to view your rectum and entire colon, while they use a flexible sigmoidoscopy to view just your rectum and lower colon. For either procedure, you’ll lie on a table while your doctor inserts a flexible tube into your anus. A small camera on the tube sends a video image of your bowel lining to a monitor. The procedures can show signs of problems in your lower gastrointestinal (GI) tract.

During these two tests, your doctor may also perform a biopsy. The doctor may take several small pieces of tissue from different areas of your bowel lining. A pathologist will look at the tissue using a microscope. You won’t feel the biopsy.

A patient lying on their side while a doctor performs a colonoscopy and a depiction of the lower GI tract examined during a colonoscopy (including the colon, rectum, colonoscope, and anus.
Colonoscopy is used to view the entire colon and rectum. © October 2014 Terese Winslow LLC, U.S. Govt. has certain rights

Colorectal transit studies

Colorectal transit studies are tests that show how well stool moves through your colon.

  • Radiopaque markers. For this test, you swallow capsules with small radioactive markers that doctors can see on an x-ray. Three to 7 days after you swallow the capsules, a health care professional will take several x-rays of your abdomen that track the movement of the markers through your colon. You eat a high-fiber diet to help stool and the markers move through your GI tract. The markers pass when you have a bowel movement.
  • Scintigraphy. For this test, you eat a meal that contains radioactive substances. The dose of radioactive substances is small, so scintigraphy isn’t likely to damage your cells. A health care professional will use computers and special cameras placed outside your body over your abdomen to create pictures of the radioactive substances as they move through your intestines.

Anorectal function tests

Anorectal function tests can show problems in your anus or rectum.

  • Anal manometry uses pressure sensors and a balloon that a health care professional inflates inside your rectum to check how sensitive your rectum is and how well it works. Anal manometry also checks the tightness of the muscles around your anus and how well they respond to nerve signals. For this test, a health care professional puts a thin tube that has pressure sensors and a balloon on its tip into your anus. Once the balloon reaches your rectum and the pressure sensors are in your anus, the health care professional slowly pulls the tube out to measure muscle tone and contractions. The test takes about 30 minutes.
  • Balloon expulsion tests consist of a health care professional filling a balloon with different amounts of water after he or she places it into your rectum. The health care professional will give you a stopwatch and instructions to go to the restroom and measure the amount of time it takes you to push the balloon out. If you can’t push out a balloon filled with less than 150 milliliters of water, or it takes longer than 1 minute to push the balloon out, you may have a problem pushing out stool.

Lower GI series

A lower GI series is an x-ray exam that doctors use to look at your large intestine. A health care professional will perform the procedure at a hospital or an outpatient center. A health care professional may give you written instructions about what to do at home before the procedure, called a bowel prep.

The health care professional may ask you to follow a clear liquid diet for 1 to 3 days before the procedure. You may also need to use a laxative or an enema before the procedure. Laxatives and enemas cause diarrhea, so you should stay close to a bathroom during the bowel prep.

For the procedure, you’ll lie on a table while your doctor inserts a flexible tube into your anus. Your doctor then fills your large intestine with barium, which makes signs of problems that may be causing constipation show up more clearly on x-rays.

Traces of barium in your large intestine can cause white or light-colored stools for several days. Enemas and repeated bowel movements may cause anal soreness. A health care professional will give you specific instructions about eating and drinking after the procedure.


Defecography is a video x-ray of the area around your anus and rectum. The procedure may show problems with how you have a bowel movement.

During the test, a health care professional fills your rectum with a soft paste that shows up on x-rays and feels like stool. You sit on a toilet next to an x-ray machine. The health care professional will ask you to first pull in and squeeze muscles to keep stool in. Then, he or she will tell you to strain to have a bowel movement. The health care professional looks for problems as you push the paste out.

Magnetic resonance imaging (MRI)

MRI machines use radio waves and magnets to produce detailed pictures of your body’s internal organs and soft tissues without using x-rays.

Patients don’t need anesthesia, although a health care professional may give light sedation, taken by mouth, to children and people with a fear of small spaces. A health care professional may inject a special dye, called contrast medium, into your body. In most cases, you’ll lie on a table that slides into a tunnel-shaped device. The tunnel may be open ended or closed at one end. A radiologist reviews the images. A doctor can use the MRI images to diagnose health problems that may be causing your constipation.

Computerized tomography (CT) scan

CT scans use x-rays and computer technology to create images. A health care professional may give you a solution to drink and an injection of contrast medium. You’ll lie on a table that slides into a tunnel-shaped device that takes the x-rays. Radiologists review the images. A doctor can use the MRI images to diagnose health problems that may be causing your constipation.

Patients don’t need anesthesia, although health care professionals may give children a sedative to help them fall asleep for the test.

Women of childbearing age should have a pregnancy test before having a CT scan. The radiation from CT scans can be harmful to a developing fetus.


How do doctors treat constipation?

Treatment for constipation depends on

  • what’s causing your constipation
  • how bad your constipation is
  • how long you’ve been constipated

Treatment for constipation may include the following:

Changes in eating, diet, and nutrition

Changes in your eating, diet, and nutrition can treat constipation. These changes include

  • drinking liquids throughout the day. A health care professional can recommend how much and what kind of liquids you should drink.
  • eating more fruits and vegetables.
  • eating more fiber.

Read about what you should eat to help prevent and relieve constipation and foods to avoid if you are constipated.

Exercise and lifestyle changes

Exercising every day may help prevent and relieve constipation.

You can also try to have a bowel movement at the same time each day. Picking a specific time of day may help you have a bowel movement regularly. For example, some people find that trying to have a bowel movement 15 to 45 minutes after breakfast helps them have a bowel movement. Eating helps your colon move stool. Make sure you give yourself enough time to have a bowel movement. You should also use the bathroom as soon as you feel the urge to have a bowel movement.

Two people walking for exercise.

Over-the-counter medicines

Your doctor may suggest using a laxative for a short time if you’re doing all the right things and are still constipated. Your doctor will tell you what type of laxative is best for you. Over-the-counter laxatives come in many forms, including liquid, tablet, capsule, powder, and granules.

If you’re taking an over-the-counter or prescription medicine or supplement that can cause constipation, your doctor may suggest you stop taking it or switch to a different one.

Bulk-forming agents. Bulk-forming agents absorb fluid in your intestines, making your stool bulkier. Bulkier stool helps trigger the bowel to contract and push stool out. Be sure to take bulk-forming agents with water or they can cause an obstruction or a blockage in your bowel. They can also cause bloating and pain in your abdomen. Brand names include

Osmotic agents. Osmotic agents help stool retain fluid. Stools with more fluid increase your number of bowel movements and soften stool. Older adults and people with heart or kidney failure should be careful when taking osmotic agents. They can cause dehydration or a mineral imbalance. Brand names include

Stool softeners. Stool softeners help mix fluid into stools to soften them. Doctors recommend stool softeners for people who should avoid straining while having a bowel movement. Doctors often recommend stool softeners after surgery or for women after childbirth. Brand names include

Lubricants. Lubricants work by coating the surface of stool, which helps the stool hold in fluid and pass more easily. Lubricants are simple, inexpensive laxatives. Doctors may recommend lubricants for people with anorectal blockage. Brand names include

  • Fleet
  • Zymenol

If these laxatives don’t work for you, your doctor may recommend other types of laxatives, including

Stimulants. Stimulant laxatives cause the intestines to contract, which moves stool. You should only use stimulants if your constipation is severe or other treatments have not worked. Brand names include

People should not use stimulant laxatives containing phenolphthalein. Phenolphthalein may increase your chances of cancer. Most laxatives sold in the United States do not contain phenolphthalein. Make sure to check the ingredients on the medicine’s package or bottle.

If you’ve been taking laxatives for a long time and can’t have a bowel movement without taking a laxative, talk with your doctor about how you can slowly stop using them. If you stop taking laxatives, over time, your colon should start moving stool normally.

Prescription medicines

If over-the-counter medicines do not relieve your symptoms, your doctor may prescribe one of the following medicines:

Chloride channel activator. If you have irritable bowel syndrome (IBS) with long-lasting or idiopathic—meaning the cause is not known—constipation, your doctor may prescribe lubiprostone (Amitiza). Lubiprostone is a chloride channel activator available with a prescription. Research has shown lubiprostone to be safe when used for 6 to 12 months. This type of medicine increases fluid in your GI tract, which helps to

  • reduce pain or discomfort in your abdomen
  • make your stool softer
  • reduce your need to strain when having a bowel movement
  • increase how often you have bowel movements

Guanylate cyclase-C agonist. If you have IBS with long-lasting or idiopathic constipation, your doctor may prescribe linaclotide (Linzess) to help make your bowel movements regular. Linaclotide is a guanylate cyclase-C agonist that eases pain in your abdomen and speeds up how often you have bowel movements.


If you have problems with the muscles that control bowel movements, your doctor may recommend biofeedback to retrain your muscles. Biofeedback uses special sensors to measure bodily functions. A video monitor shows the measurements as line graphs, and sounds from the equipment tell you when you’re using the correct muscles. By watching the monitor and listening to the sounds, you learn how to change the muscle function. Practicing at home can improve muscle function. You may have to practice for 3 months before you get all the benefit from the training.


You may need surgery to treat an anorectal blockage caused by rectal prolapse if other treatments don’t work. You may need surgery to remove your colon if your colon muscles don’t work correctly. Your doctor can tell you about the benefits and risks of surgery.

How do doctors treat complications of constipation?

Doctors can treat or tell you how to treat complications of constipation. Hemorrhoids, anal fissures, rectal prolapse, and fecal impaction all have different treatments.


You can treat hemorrhoids at home by

  • making dietary changes to prevent constipation
  • taking warm tub baths
  • applying over-the-counter hemorrhoid cream to the area or using suppositories—a medicine you insert into your rectum—before bedtime

Talk with your doctor about hemorrhoids that do not respond to at-home treatments.

Anal fissures

You can treat anal fissures at home by

  • making changes in your diet to prevent constipation
  • applying over-the-counter hemorrhoid cream to numb the area or relax your muscles
  • using stool softeners
  • taking warm tub baths

Your doctor may recommend surgery to treat anal fissures that don’t heal with at-home treatments.

Rectal prolapse

Your doctor may be able to treat your rectal prolapse in his or her office by manually pushing the rectum back through your anus. If you have a severe or chronic—long-lasting—rectal prolapse, you may need surgery. The surgery will strengthen and tighten your anal sphincter muscle and repair the prolapsed lining. You can help prevent rectal prolapse caused by constipation by not straining during a bowel movement.

Fecal impaction

You can soften a fecal impaction with mineral oil that you take by mouth or through an enema. After softening the impaction, a health care professional may break up and remove part of the hardened stool by inserting one or two gloved, lubricated fingers into your anus.

Eating, Diet, & Nutrition

How can your diet help prevent and relieve constipation?

You can drink water and other fluids, such as fruit and vegetable juices and clear soups, to help the fiber in your diet work better. This change should make your stools more normal and regular. Ask your doctor about how much you should drink each day based on your health and activity level and where you live.

Depending on their age and sex, adults should get 22 to 34 grams of fiber a day.3 Older adults sometimes don’t get enough fiber in their diets, because they may lose interest in food. If you are older and have lost interest in food, talk with your doctor if

  • food doesn’t taste the same as it once did
  • you don’t feel hungry as often
  • you don’t want to cook
  • you have problems chewing or swallowing

Talk with your doctor to plan a diet with the right amount of fiber for you. Be sure to add fiber to your diet a little at a time so that your body gets used to the change.

Use this table as a tool to help replace less healthy foods with foods that have fiber.

Portions of food for constipation
Examples of Foods That Have Fiber 3
Beans, cereals, and breads
½ cup of beans (navy, pinto, kidney, etc.), cooked 6.2–9.6 grams
½ cup of shredded wheat, ready-to-eat cereal 2.7-3.8 grams
⅓ cup of 100% bran, ready-to-eat cereal 9.1 grams
1 small oat bran muffin 3.0 grams
1 whole-wheat English muffin  4.4 grams
1 small apple, with skin 3.6 grams
1 medium pear, with skin 5.5 grams
½ cup of raspberries 4.0 grams
½ cup of stewed prunes 3.8 grams
½ cup of winter squash, cooked 2.9 grams
1 medium sweet potato, baked in skin 3.8 grams
½ cup of green peas, cooked 3.5-4.4 grams
1 small potato, baked, with skin 3.0 grams
½ cup of mixed vegetables, cooked 4.0 grams
½ cup of broccoli, cooked  2.6-2.8 grams
½ cup of greens (spinach, collards, turnip greens), cooked 2.5-3.5 grams

What should you avoid eating if you’re constipated?

If you’re constipated, try not to eat too many foods with little or no fiber, such as

  • cheese
  • chips
  • fast food
  • ice cream
  • meat
  • prepared foods, such as some frozen meals and snack foods
  • processed foods, such as hot dogs or some microwavable dinners


Clinical Trials

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other components of the National Institutes of Health (NIH) conduct and support basic and clinical research into many digestive disorders.

What are clinical trials and are they right for you?

Clinical trials are part of clinical research and at the heart of all medical advances. Clinical trials look at new ways to prevent, detect, or treat disease. Researchers also use clinical trials to look at other aspects of care, such as improving the quality of life for people with chronic illnesses. Find out if clinical trials are right for you.

What clinical trials are open?

Clinical trials that are currently open and are recruiting can be viewed at​

February 2015

This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings through its clearinghouses and education programs to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.