What is Constipation?

On this page you will learn about constipation in adults. Learn about constipation in children.

What is Constipation?

Illustration of What is Constipation

Constipation is the infrequent passage or evacuation of stool from the bowel. People who are constipated may find it difficult and painful to have a bowel movement. Symptoms of constipation often include feeling bloated, uncomfortable, and sluggish.

There are some inaccuracies found in the medical and lay literature regarding how often one should have a bowel movement. It is a myth to assume that people who have a bowel movement every day cannot be constipated or irregular. In fact, it may be normal for a person to evacuate three times a day; independent of how often meals are consumed. In nature, it is normal (and regular) for animals to evacuate their bowels after every meal. Humans however, do not follow this animal model of bowel regularity. This may be because humans have learned to control their bowel movements, in response to perceived social rules and values. For whatever reason, human beings are the only animals found in natures that do not evacuate their bowels after every meal. In view of the frequency of animal bowel movements found in nature, and the multiple variations found in the frequency of bowel evacuations in human beings, constipation cannot be defined in terms of the number of bowel movements in any period of time. People are constipated if their evacuations do not correspond in frequency, consistency and quantity with what they eat.

At one time or another almost everyone gets constipated. Poor diet and lack of exercise is usually the cause. In most cases, constipation is temporary and not serious. Understanding causes, prevention, and treatment will help most people find relief.


Who Gets Constipated?

According to the 1991 National Health Interview Survey, about
4 1/2 million people in the United States say they are constipated
most or all of the time. Those reporting constipation most
often are women, children, and adults age 65 and over. Pregnant
women also complain of constipation, and it is a common problem
following childbirth or surgery.

Constipation is the most common gastrointestinal
complaint in the United States, resulting in about 2 million
annual visits to the doctor. However, most people treat themselves
without seeking medical help, as is evident from the $725
million Americans spend on laxatives each year.


What Causes Constipation?

To understand constipation, it helps to know how the colon
(large intestine) works. As food moves through it, the colon
absorbs water while forming waste products, or stool. Muscle
contractions in the colon push the stool toward the rectum.
By the time stool reaches the rectum, it is solid because
most of the water has been absorbed. (See
figure 1.

The hard and dry stools of constipation
occur when the colon absorbs too much water. This happens
because the colon’s muscle contractions are slow or sluggish,
causing the stool to move through the colon too slowly. Figure
2 lists the most common causes of constipation.

Common Causes of Constipation

Not enough fiber in diet
Not enough liquids
Lack of exercise

Irritable bowel syndrome
Changes in life or routine such as pregnancy, older
age, and travel
Abuse of laxatives
Ignoring the urge to have a bowel movement
Specific diseases such as multiple sclerosis and lupus

Problems with the colon and rectum

Problems with intestinal function (Chronic idiopathic

Fig. 2

Colonic Irrigation

Colonic hydrotherapy or irrigation is a safe, gentle, warm water cleansing of the colon that can help to eliminate stored fecal matter, gas, mucus, and toxic substances from the colon. Water is introduced at a low gravitational pressure, or special equipment is used that feature temperature controlled water mixing and back flow prevention valves. An important indication for colon hydrotherapy is constipation. These treatments can help retrain a chronically sluggish bowel.


The most common cause of constipation is a diet low in fiber
found in vegetables, fruits, and whole grains and high in
fats found in cheese, eggs, and meats. People who eat plenty
of high-fiber foods are less likely to become constipated.
For more information, view our High Fiber Diet page.

Fiber–soluble and insoluble–is the part of fruits, vegetables,
and grains that the body cannot digest. Soluble fiber dissolves
easily in water and takes on a soft, gel-like texture in the
intestines. Insoluble fiber passes almost unchanged through
the intestines. The bulk and soft textures of fiber help prevent
hard, dry stools that are difficult to pass.

On average, Americans eat about 5 to 20 grams of fiber daily,
short of the 20 to 35 grams recommended by the American Dietetic
Association. Both children and adults eat too many refined
and processed foods in which the natural fiber is removed.

A low-fiber diet also plays a key role in constipation among
older adults. They often lack interest in eating and may choose
fast foods low in fiber. In addition, loss of teeth may force
older people to eat soft foods that are processed and low
in fiber.


Not Enough Liquids

Liquids like water and juice add fluid to the colon and bulk
to stools, making bowel movements softer and easier to pass.
People who have problems with constipation should drink enough
of these liquids every day, about eight 8-ounce glasses. Other
liquids, like coffee and soft drinks, that contain caffeine
seem to have a dehydrating effect.

Lack of Exercise

Lack of exercise can lead to constipation, although doctors
do not know precisely why. For example, constipation often
occurs after an accident or during an illness when one must
stay in bed and cannot exercise.


Pain medications (especially narcotics), antacids that contain
aluminum, antispasmodics, antidepressants, iron supplements,
diuretics, and anticonvulsants for epilepsy can slow passage
of bowel movements.

Irritable Bowel Syndrome (IBS)

Some people with IBS, also known as spastic colon, have spasms
in the colon that affect bowel movements. Constipation and
diarrhea often alternate, and abdominal cramping, gassiness,
and bloating are other common complaints. Although IBS can
produce lifelong symptoms, it is not a life-threatening condition.
It often worsens with stress, but there is no specific cause
or anything unusual that the doctor can see in the colon.

Changes in Life or Routine
During pregnancy, women may be constipated because of hormonal
changes or because the heavy uterus compresses the intestine.
Aging may also affect bowel regularity because a slower metabolism
results in less intestinal activity and muscle tone. In addition,
people often become constipated when traveling because their
normal diet and daily routines are disrupted.

Abuse of Laxatives
Myths about constipation have led to a serious abuse of laxatives.
This is common among older adults who are preoccupied with
having a daily bowel movement.

Laxatives usually are not necessary
and can be habit-forming. The colon begins to rely on laxatives
to bring on bowel movements. Over time, laxatives can damage
nerve cells in the colon and interfere with the colon’s natural
ability to contract. For the same reason, regular use of enemas
can also lead to a loss of normal bowel function.

Ignoring the Urge to Have a Bowel

People who ignore the urge to have a bowel movement may eventually
stop feeling the urge, which can lead to constipation. Some
people delay having a bowel movement because they do not want
to use toilets outside the home. Others ignore the urge because
of emotional stress or because they are too busy. Children
may postpone having a bowel movement because of stressful
toilet training or because they do not want to interrupt their

Specific Diseases

Diseases that cause constipation include neurological disorders,
metabolic and endocrine disorders, and systemic conditions
that affect organ systems. These disorders can slow the movement
of stool through the colon, rectum, or anus. Figure 3 lists
the diseases that cause constipation.

Diseases That Cause Constipation

Neurological disorders that may cause constipation
Multiple sclerosis

Parkinson’s disease
Chronic idiopathic intestinal pseudo-obstruction
Spinal cord injuries.

Metabolic and endocrine conditions include:

Underactive or overactive thyroid gland

Systemic disorders include:

Fig. 3


Problems with the Colon and Rectum

Intestinal obstruction, scar tissue (adhesions), diverticulosis,
tumors, colorectal stricture, Hirschsprung’s disease, or cancer
can compress, squeeze, or narrow the intestine and rectum
and cause constipation.

Problems with Intestinal Function
(Chronic Idiopathic Constipation)

Also known as functional constipation, chronic idiopathic
(of unknown origin) constipation is rare. However, some people
are chronically constipated and do not respond to standard
treatment. This chronic constipation may be related to multiple
problems with hormonal control or with nerves and muscles
in the colon, rectum, or anus. Functional constipation occurs
in both children and adults and is most common in women.

Colonic inertia and delayed transit
are two types of functional constipation caused by decreased
muscle activity in the colon. These syndromes may affect the
entire colon or may be confined to the left or lower (sigmoid)

Functional constipation that stems
from abnormalities in the structure of the anus and rectum
is known as anorectal dysfunction, or anismus. These abnormalities
result in an inability to relax the rectal and anal muscles
that allow stool to exit.


What Diagnostic Tests Are Used?

Most people do not need extensive testing and can be treated
with changes in diet and exercise. For example, in young people
with mild symptoms, a medical history and physical examination
may be all the doctor needs to suggest successful treatment.
The tests the doctor performs depends on the duration and
severity of the constipation, the person’s age, and whether
there is blood in stools, recent changes in bowel movements,
or weight loss.

Medical History

The doctor may ask a patient to describe his or her constipation,
including duration of symptoms, frequency of bowel movements,
consistency of stools, presence of blood in the stool, and
toilet habits (how often and where one has bowel movements).
Recording eating habits, medication, and level of physical
activity or exercise also helps the doctor determine the cause
of constipation.

Physical Examination

A physical exam may include a digital rectal exam with a gloved,
lubricated finger to evaluate the tone of the muscle that
closes off the anus (anal sphincter) and to detect tenderness,
obstruction, or blood. In some cases, blood and thyroid tests
may be necessary.

Extensive testing usually is reserved
for people with severe symptoms, for those with sudden changes
in number and consistency of bowel movements or blood in the
stool, and for older adults. Because of an increased risk
of colorectal cancer in older adults, the doctor may use these
tests to rule out a diagnosis of cancer:

  • Barium enema x-ray
  • Sigmoidoscopy or colonoscopy
  • Colorectal transit study
  • Anorectal function tests.

Barium Enema X-Ray

A barium enema x-ray involves viewing the rectum, colon, and
lower part of the small intestine to locate any problems.
This part of the digestive tract is known as the bowel. This
test may show intestinal obstruction and Hirschsprung’s disease,
a lack of nerves within the colon.

The night before the test, bowel cleansing,
also called bowel prep, is necessary to clear the lower digestive
tract. The patient drinks 8 ounces of a special liquid every
15 minutes for about 4 hours. This liquid flushes out the
bowel. A clean bowel is important, because even a small amount
of stool in the colon can hide details and result in an inaccurate

Because the colon does not show up
well on an x-ray, the doctor fills the organs with a barium
enema, a chalky liquid to make the area visible. Once the
mixture coats the organs, x-rays are taken that reveal their
shape and condition. The patient may feel some abdominal cramping
when the barium fills the colon, but usually feels little
discomfort after the procedure. Stools may be a whitish color
for a few days after the exam.

Sigmoidoscopy or Colonoscopy

An examination of the rectum and lower colon (sigmoid) is
called a sigmoidoscopy. An examination of the rectum and entire
colon is called a colonoscopy.

The night before a sigmoidoscopy,
the patient usually has a liquid dinner and takes an enema
in the early morning. A light breakfast and a cleansing enema
an hour before the test may also be necessary.

To perform a sigmoidoscopy, the doctor
uses a long, flexible tube with a light on the end called
a sigmoidoscope to view the rectum and lower colon. First,
the doctor examines the rectum with a gloved, lubricated finger.
Then, the sigmoidoscope is inserted through the anus into
the rectum and lower colon. The procedure may cause a mild
sensation of wanting to move the bowels and abdominal pressure.
Sometimes the doctor fills the organs with air to get a better
view. The air may cause mild cramping.

To perform a colonoscopy, the doctor
uses a flexible tube with a light on the end called a colonoscope
to view the entire colon. This tube is longer than a sigmoidoscope.
The same bowel cleansing used for the barium x-ray is needed
to clear the bowel of waste. The patient is lightly sedated
before the exam. During the exam, the patient lies on his
or her side and the doctor inserts the tube through the anus
and rectum into the colon. If an abnormality is seen, the
doctor can use the colonoscope to remove a small piece of
tissue for examination (biopsy). The patient may feel gassy
and bloated after the procedure.

Colorectal Transit Study

This test, reserved for those with chronic constipation, shows
how well food moves through the colon. The patient swallows
capsules containing small markers, which are visible on x-ray.
The movement of the markers through the colon is monitored
with abdominal x-rays taken several times 3 to 7 days after
the capsule is swallowed. The patient follows a high-fiber
diet during the course of this test.

Anorectal Function Tests
These tests diagnose constipation caused by abnormal functioning
of the anus or rectum (anorectal function). Anorectal manometry
evaluates anal sphincter muscle function. A catheter or air-filled
balloon inserted into the anus is slowly pulled back through
the sphincter muscle to measure muscle tone and contractions.

Defecography is an x-ray of the anorectal
area that evaluates completeness of stool elimination, identifies
anorectal abnormalities, and evaluates rectal muscle contractions
and relaxation. During the exam, the doctor fills the rectum
with a soft paste that is the same consistency as stool. The
patient sits on a toilet positioned inside an x-ray machine
and then relaxes and squeezes the anus and expels the solution.
The doctor studies the x-rays for anorectal problems that
occurred while the patient emptied the paste.


How Is Constipation Treated?

Although treatment depends on the cause, severity, and duration,
in most cases dietary and lifestyle changes will help relieve
symptoms and help prevent constipation.


A diet with enough fiber (20 to 35 grams each day) helps form
soft, bulky stool. A doctor or dietitian can help plan an
appropriate diet. High-fiber foods include beans; whole grains
and bran cereals; fresh fruits; and vegetables such as asparagus,
brussels sprouts, cabbage, and carrots. For people prone to
constipation, limiting foods that have little or no fiber
such as ice cream, cheese, meat, and processed foods is also

Lifestyle Changes

Other changes that can help treat and prevent constipation
include drinking enough water and other liquids such as fruit
and vegetable juices and clear soup, engaging in daily exercise,
and reserving enough time to have a bowel movement. In addition,
the urge to have a bowel movement should not be ignored.


Most people who are mildly constipated do not need laxatives. However, for those who have made lifestyle changes and are still constipated, doctors may recommend laxatives, enemas, or colonic irrigation for a limited time. These treatments can help retrain a chronically sluggish bowel. For children, short-term treatment with laxatives, along with retraining to establish regular bowel habits, also helps prevent constipation.

A doctor should determine when a patient needs a laxative and which form is best. Laxatives taken by mouth are available in liquid, tablet, gum, powder, and granule forms. They work in various ways:

Bulk-forming laxatives generally are considered the safest but can interfere with absorption of some medicines. These laxatives, also known as fiber supplements, are taken with water. They absorb water in the intestine and make the stool softer. Brand names include Metamucil®, Citrucel®, Konsyl®, and Serutan®.

Stimulants cause rhythmic muscle contractions in the intestines. Brand names include Correctol®, Dulcolax®, Purge®, Feen-A-Mint®, and Senokot®. Studies suggest that phenolphthalein, an ingredient in some stimulant laxatives, might increase a person’s risk for cancer. The Food and Drug Administration has proposed a ban on all over-the-counter products containing phenolphthalein. Most laxative makers have replaced or plan to replace phenolphthalein with a safer ingredient.

Stool softeners provide moisture to the stool and prevent dehydration. These laxatives are often recommended after childbirth or surgery. Products include Colace®, Dialose®, and Surfak®.

Lubricants grease the stool enabling it to move through the intestine more easily. Mineral oil is the most common lubricant.

Saline laxatives act like a sponge to draw water into the colon for easier passage of stool. Laxatives in this group include Milk of Magnesia®, Citrate of Magnesia®, and Haley’s M-O®.

Emotional factors enter into the action of evacuation, causing some individuals to experience subjective constipation. Subjective constipation is a common occurrence. It exists only in the mind prednisone of the individual experiencing it, and constitutes the chief basis for the over-consumption and abuse of laxatives.

People who are dependent on laxatives need to slowly stop using the medications. A doctor can assist in this process. In most people, this restores the colon’s natural ability to contract.


Other Treatment

Treatment may be directed at a specific cause. For example,
the doctor may recommend discontinuing medication or performing
surgery to correct an anorectal problem such as rectal prolapse.

People with chronic constipation caused
by anorectal dysfunction can use biofeedback to retrain the
muscles that control release of bowel movements. Biofeedback
involves using a sensor to monitor muscle activity that at
the same time can be displayed on a computer screen allowing
for an accurate assessment of body functions. A health care
professional uses this information to help the patient learn
how to use these muscles.

Surgical removal of the colon may be an option for people with severe symptoms caused by colonic inertia. However, the benefits of this surgery must be weighed against possible complications, which include abdominal painand diarrhea.


Can Constipation Be Serious?

Sometimes constipation can lead to complications. These complications
include hemorrhoids caused by straining to have a bowel movement
or anal fissures (tears in the skin around the anus) caused
when hard stool stretches the sphincter muscle. As a result,
rectal bleeding may occur that appears as bright red streaks
on the surface of the stool. Treatment for hemorrhoids may
include warm tub baths, ice packs, and application of a cream
to the affected area.

Treatment for anal fissure may include
stretching the sphincter muscle or surgical removal of tissue
or skin in the affected area. Sometimes straining causes a
small amount of intestinal lining to push out from the anal
opening. This condition is known as rectal prolapse and may
lead to secretion of mucus from the anus. Usually, eliminating
the cause of the prolapse such as straining or coughing is
the only treatment necessary. Severe or chronic prolapse requires
surgery to strengthen and tighten the anal sphincter muscle
or to repair the prolapsed lining.

Constipation may also cause hard
stool to pack the intestine and rectum so tightly that the
normal pushing action of the colon is not enough to expel
the stool. This condition, called fecal impaction, occurs
most often in children and older adults. An impaction can
be softened with mineral oil taken by mouth and an enema.
After softening the impaction, the doctor may break up and
remove part of the hardened stool by inserting one or two
fingers in the anus.


Points to Remember

Constipation affects almost everyone at one time or another.

Many people think they are constipated
when, in fact, their bowel movements are regular.

The most common causes of constipation
are poor diet and lack of exercise.

Additional causes of constipation
include medications, irritable bowel syndrome, abuse of laxatives,
and specific diseases.

A medical history and physical examination
may be the only diagnostic tests needed before the doctor
suggests treatment.

In most cases, following these simple
tips will help relieve symptoms and prevent recurrence of

Eat a well-balanced, high-fiber diet
that includes beans, bran, whole grains, fresh fruits, and

  • Drink plenty of liquids.
  • Exercise regularly.
  • Set aside time after breakfast
    or dinner for undisturbed visits to the toilet.
  • Do not ignore the urge to have
    a bowel movement.
  • Understand that normal bowel habits
  • Whenever a significant or prolonged
    change in bowel habits occurs, check with a doctor.

Most people with mild constipation
do not need laxatives. However, doctors may recommend laxatives
for a limited time for people with chronic constipation.

Additional Resources

International Foundation for Functional Gastrointestinal Disorders

P.O. Box 17864

Milwaukee, WI 53217
(414) 964-1799

Intestinal Disease Foundation
1323 Forbes Avenue, Suite 200
Pittsburgh, PA 15219
(412) 261-5888