Constipation
Constipation is passage of small amounts of hard, dry bowel movements, usually fewer than three times a week. People who are constipated may find it difficult and painful to have a bowel movement. Other symptoms of constipation include feeling bloated, uncomfortable, and sluggish.
At one time or another, almost everyone gets constipated. Poor diet and lack of exercise are usually the causes. In most cases, constipation is temporary and not serious. Understanding its causes, prevention, and treatment will help most people find relief.
What causes constipation?
To understand constipation, it helps to know how the colon (large intestine) works. As food moves through the colon, it 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.
The hard and dry stools of constipation occur when the colon absorbs too much water or if the colon's muscle contractions are slow or sluggish, causing the stool to move through the colon too slowly. Common causes of constipation are
- not enough fiber in the diet
- not enough liquids
- lack of exercise
- medications
- 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 stroke (by far the most common)
- problems with the colon and rectum
- problems with intestinal function (chronic idiopathic constipation)
Not Enough Fiber in the Diet
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.
Fiber—both 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 through the intestines almost unchanged. The bulk and soft texture of fiber help prevent hard, dry stools that are difficult to pass.
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. Liquids that contain caffeine, like coffee and cola drinks, and alcohol 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.
Medications
Some medications can cause constipation. They include
- pain medications (especially narcotics)
- antacids that contain aluminum and calcium
- blood pressure medications (calcium channel blockers)
- antiparkinson drugs
- antispasmodics
- antidepressants
- iron supplements
- diuretics
- anticonvulsants
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 people 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 Movement
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.
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). A record of eating habits, medication, and level of physical activity or exercise will also help the doctor determine the cause of constipation.
The clinical definition of constipation is any two of the following symptoms for at least 12 weeks (not necessarily consecutive) in the previous 12 months:
- straining during bowel movements
- lumpy or hard stool
- sensation of incomplete evacuation
- sensation of anorectal blockage/obstruction
- fewer than three bowel movements per week
How is constipation treated?
Although treatment depends on the cause, severity, and duration, in most cases dietary and lifestyle changes will help relieve symptoms of constipation and help prevent it.
Diet
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 important.
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 soups, 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.
Laxatives
Most people who are mildly constipated do not need laxatives. However, for those who have made diet and lifestyle changes and are still constipated, doctors may recommend laxatives or enemas 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, 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 and Surfak.
- Lubricants grease the stool enabling it to move through the intestine more easily. Mineral oil is the most common example.
- 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 and Haley's M-O.
People who are dependent on laxatives need to slowly stop using them. A doctor can assist in this process. In most people, this restores the colon's natural ability to contract.
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 constipation:
- Eat a well-balanced, high-fiber diet that includes beans, bran, whole grains, fresh fruits, and vegetables.
- 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 vary.
- 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.

