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What is constipation?
Constipation is generally described as having fewer than three bowel movements a week. Chronic constipation is infrequent bowel movements or difficult passage of stools that persists for several weeks or longer.
Though occasional constipation is very common. When its present for a long time, its called chronic constipation. Some people experience chronic constipation that can interfere with their ability to go about their daily tasks. Chronic constipation may also cause excessive straining to have a bowel movement and other signs and symptoms.
Treatment for chronic constipation depends in part on the underlying cause. However, in some cases, a cause is never found.
What are the symptoms?
Signs and symptoms of chronic constipation include:
- Passing fewer than three stools a week
- Having lumpy or hard stools
- Straining to have bowel movements
- Feeling as though there's a blockage in your rectum that prevents bowel movements
- Feeling as though you can't completely empty the stool from your rectum
- Needing help to empty your rectum, such as using your hands to press on your abdomen and using a finger to remove stool from your rectum
- Constipation may be considered chronic if you've experienced two or more of these symptoms for the last three months.
What are the causes?
Constipation most commonly occurs when waste or stool moves too slowly through the digestive tract or cannot be eliminated effectively from the rectum, which may cause the stool to become hard and dry. Chronic constipation has many possible causes.
Blockages in the colon or rectum
Blockages in the colon or rectum may slow or stop stool movement. Causes include:
- Anal fissure
- Bowel obstruction
- Colon cancer
- Narrowing of the colon (bowel stricture)
- Other abdominal cancer that presses on the colon
- Rectal cancer
- Rectum bulge through the back wall of the vagina (rectocele)
Problems with the nerves around the colon and rectum
Neurological problems can affect the nerves that cause muscles in the colon and rectum to contract and move stool through the intestines. Causes include:
- Autonomic neuropathy
- Multiple sclerosis
- Parkinson's disease
- Spinal cord injury
Difficulty with the muscles involved in elimination
Problems with the pelvic muscles involved in having a bowel movement may cause chronic constipation. These problems may include:
- Inability to relax the pelvic muscles to allow for a bowel movement (anismus)
- Pelvic muscles don't coordinate relaxation and contraction correctly (dyssynergia)
- Weakened pelvic muscles
Conditions that affect hormones in the body
Hormones help balance fluids in your body. Diseases and conditions that upset the balance of hormones may lead to constipation, including:
- Overactive parathyroid gland (hyperparathyroidism)
- Underactive thyroid (hypothyroidism)
What are the risk factors?
Factors that may increase your risk of chronic constipation include:
- Being an older adult
- Being a woman
- Being dehydrated
- Eating a diet that's low in fiber
- Getting little or no physical activity
- Taking certain medications, including sedatives, narcotics, some antidepressants or medications to lower blood pressure
- Having a mental health condition such as depression or an eating disorder
What complications can happen?
Complications of chronic constipation include:
- Swollen veins in your anus (hemorrhoids). Straining to have a bowel movement may cause swelling in the veins in and around your anus.
- Torn skin in your anus (anal fissure). A large or hard stool can cause tiny tears in the anus.
- Stool that can't be expelled (fecal impaction). Chronic constipation may cause an accumulation of hardened stool that gets stuck in your intestines.
- Intestine that protrudes from the anus (rectal prolapse). Straining to have a bowel movement can cause a small amount of the rectum to stretch and protrude from the anus.
How to prevent constipation?
The following can help you avoid developing chronic constipation.
- Include plenty of high-fiber foods in your diet, including beans, vegetables, fruits, whole grain cereals and bran.
- Eat fewer foods with low amounts of fiber such as processed foods, and dairy and meat products.
- Drink plenty of fluids.
- Stay as active as possible and try to get regular exercise.
- Try to manage stress.
- Don't ignore the urge to pass stool.
- Try to create a regular schedule for bowel movements, especially after a meal.
- Make sure children who begin to eat solid foods get plenty of fiber in their diets.
How is constipation diagnosed?
In addition to a general physical exam and a digital rectal exam, doctors use the following tests and procedures to diagnose chronic constipation and try to find the cause:
Blood tests. Your doctor will look for a systemic condition such as low thyroid (hypothyroidism).
Examination of the rectum and lower, or sigmoid, colon (sigmoidoscopy). In this procedure, your doctor inserts a lighted, flexible tube into your anus to examine your rectum and the lower portion of your colon.
Examination of the rectum and entire colon (colonoscopy). This diagnostic procedure allows your doctor to examine the entire colon with a flexible, camera-equipped tube.
Evaluation of anal sphincter muscle function (anorectal manometry). In this procedure, your doctor inserts a narrow, flexible tube into your anus and rectum and then inflates a small balloon at the tip of the tube. The device is then pulled back through the sphincter muscle. This procedure allows your doctor to measure the coordination of the muscles you use to move your bowels.
Evaluation of anal sphincter muscle speed (balloon expulsion test). Often used along with anorectal manometry, this test measures the amount of time it takes for you to push out a balloon that has been filled with water and placed in your rectum.
Evaluation of how well food moves through the colon (colonic transit study). In this procedure, you may swallow a capsule that contains either a radiopaque marker or a wireless recording device. The progress of the capsule through your colon will be recorded over several days and be visible on X-rays.
In some cases, you may eat radiocarbon-activated food and a special camera will record its progress (scintigraphy). Your doctor will look for signs of intestinal muscle dysfunction and how well food moves through your colon.
An X-ray of the rectum during defecation (defecography). During this procedure, your doctor inserts a soft paste made of barium into your rectum. You then pass the barium paste as you would stool. The barium shows up on X-rays and may reveal a prolapse or problems with muscle function and muscle coordination.
MRI defecography. During this procedure, as in barium defecography, a doctor will insert contrast gel into your rectum. You then pass the gel. The MRI scanner can visualize and assess the function of the defecation muscles. This test also can diagnose problems that can cause constipation, such as rectocele or rectal prolapse.
What is the treatment?
Treatment for chronic constipation usually begins with diet and lifestyle changes meant to increase the speed at which stool moves through your intestines. If those changes don't help, your doctor may recommend medications or surgery.
Diet and lifestyle changes
Your doctor may recommend the following changes to relieve your constipation:
Increase your fiber intake. Adding fiber to your diet increases the weight of your stool and speeds its passage through your intestines. Slowly begin to eat more fresh fruits and vegetables each day. Choose whole-grain breads and cereals.
Your doctor may recommend a specific number of grams of fiber to consume each day. In general, aim for 14 grams of fiber for every 1,000 calories in your daily diet.
A sudden increase in the amount of fiber you eat can cause bloating and gas, so start slowly and work your way up to your goal over a few weeks.
Exercise most days of the week. Physical activity increases muscle activity in your intestines. Try to fit in exercise most days of the week. If you do not already exercise, talk to your doctor about whether you are healthy enough to start an exercise program.
Don't ignore the urge to have a bowel movement. Take your time in the bathroom, allowing yourself enough time to have a bowel movement without distractions and without feeling rushed.
Several types of laxatives exist. Each works somewhat differently to make it easier to have a bowel movement. The following are available over the counter:
Fiber supplements. Fiber supplements add bulk to your stool. These include psyllium (Metamucil, Konsyl), calcium polycarbophil (FiberCon) and methylcellulose fiber (Citrucel).
Stimulants. Stimulants including bisacodyl (Dulcolax) cause your intestines to contract.
Osmotics. Osmotic laxatives help fluids move through the colon. Examples include oral magnesium hydroxide (Phillips Milk of Magnesia), magnesium citrate, lactulose, polyethylene glycol (Movicol / Kleen Prep).
Lubricants. Lubricants such as mineral oil enable stool to move through your colon more easily.
Stool softeners. Stool softeners such as docusate sodium (Colace) and docusate calcium (Surfak) moisten the stool by drawing water from the intestines.
Enemas and suppositories. Sodium phosphate (Fleet), soapsuds or tap water enemas can be useful to soften stool and produce a bowel movement. Glycerin or bisacodyl suppositories also can soften stool.
If over-the-counter medications don't help your chronic constipation, your doctor may recommend a prescription medication, especially if you have irritable bowel syndrome.
Medications that draw water into your intestines. A number of prescription medications are available to treat chronic constipation. Lubiprostone (Amitiza) and linaclotide (Linzess), work by drawing water into your intestines and speeding up the movement of stool.
Other types of medications. Misoprostol (Cytotec), colchicine/probenecid (Col-Probenecid) and onabotulinumtoxinA (also called botulinum toxin type A or Botox) all work in different ways and may be used to treat chronic constipation.
Training your pelvic muscles
Biofeedback training involves working with a therapist who uses devices to help you learn to relax and tighten the muscles in your pelvis. Relaxing your pelvic floor muscles at the right time during defecation can help you pass stool more easily.
During a biofeedback session, a special tube (catheter) to measure muscle tension is inserted into your rectum. The therapist guides you through exercises to alternately relax and tighten your pelvic muscles. A machine will gauge your muscle tension and use sounds or lights to help you understand when you've relaxed your muscles.
Place of surgery
Surgery may be an option if you have tried other treatments and your chronic constipation is caused by a blockage, rectocele, anal fissure or stricture.
For people who have tried other treatments without success and who have abnormally slow movement of stool through the colon, surgical removal of part of the colon may be an option. Surgery to remove the entire colon is rarely necessary.