Functional disorders are those in which the bowel looks
normal but doesn’t work properly. They are the most common problems affecting
the colon and rectum, and include constipation and irritable bowel syndrome
(IBS). The primary causes for functional disorders include:
- Eating a diet low in fiber
- Not getting enough exercise
- Traveling or other changes in routine
- Eating large amounts of dairy products
- Being stressed
- Resisting the urge to have a bowel movement
- Resisting the urge to have bowel movements due to pain from hemorrhoids
- Overusing laxatives (stool softeners) that, over time, weaken the bowel muscles
- Taking antacid medicines containing calcium or aluminum
- Taking certain medicines (especially antidepressants, iron pills, and
strong pain medicines such as narcotics)
- Being pregnant
Constipation is the difficult passage of stools (bowel
movements) or the infrequent (less than three times a week) or incomplete
passage of stools. Constipation is usually caused by inadequate "roughage" or
fiber in the diet, or a disruption of the regular routine or diet. Constipation
causes a person to strain during a bowel movement. It might include small, hard
stools, and sometimes causes anal problems such as fissures and hemorrhoids.
Constipation is rarely the sign of a more serious medical condition.
Treatment of constipation includes increasing the amount of
fiber you eat, exercising regularly, and moving your bowels when you have the
urge (resisting the urge causes constipation). If these treatment methods don’t
work, laxatives are a temporary solution. Note that the overuse of laxatives can
actually aggravate symptoms of constipation. Always follow the package
instructions on the laxative medicine, as well as the advice of your doctor.
Irritable bowel syndrome (IBS)
Irritable bowel syndrome (also called spastic colon, irritable
colon, or nervous stomach) is a condition in which the colon muscle contracts
more readily than in people without IBS. A number of factors can trigger IBS
including certain foods, medicines, and emotional stress. Symptoms of IBS
include abdominal pain and cramps, excess gas, bloating, and a change in bowel
habits such as harder, looser, or more urgent stools than normal. Often people
with IBS have alternating constipation and diarrhea.
Treatment includes avoiding caffeine, increasing fiber in the
diet, monitoring which foods trigger IBS (and avoiding these foods), minimizing
stress or learning different ways to cope with stress, and sometimes taking
medicines as prescribed by your health care provider.
Structural disorders are those in which the bowel looks abnormal
and doesn’t work properly. Sometimes, the structural abnormality needs to be
removed surgically. The most common structural disorders are those affecting the
anus, as well as diverticular disease and cancer.
Hemorrhoids are swollen blood vessels that line
the anal opening caused by chronic excess pressure from straining during a bowel
movement, persistent diarrhea, or pregnancy. There are two types of hemorrhoids:
internal and external.
Internal hemorrhoids are normal structures cushioning the lower
rectum and protecting it from damage by stool. When they fall down
into the anus as a result of straining, they become irritated and
start to bleed. Ultimately, internal hemorrhoids can fall down
enough to prolapse (sink or protrude) out of the anus.
Treatment includes improving bowel habits (such as
avoiding constipation, not straining during bowel movements, and
moving your bowels when you have the urge), using elastic bands to
pull the internal hemorrhoids back into the rectum, or removing them
surgically. Surgery is needed only for a small number patients with
very large, painful, and persistent hemorrhoids.
External hemorrhoids are veins that lie just under the skin on the
outside of the anus. Sometimes, after straining, the external
hemorrhoidal veins burst and a blood clot forms under the skin. This
very painful condition is called a pile.
Treatment includes removing the clot and vein under local anesthesia in the doctor’s office.
Anal fissures are splits or cracks in the lining
of the anal opening. The most common cause of an anal fissure is the passage of
very hard or watery stools. The crack in the anal lining exposes the underlying
muscles that control the passage of stool through the anus and out of the body.
An anal fissure is one of the most painful problems because the exposed muscles
become irritated from exposure to stool or air, and leads to intense burning
pain, bleeding, or spasm after bowel movements.
Initial treatment for anal fissures includes pain medicine,
dietary fiber to reduce the occurrence of large, bulky stools, and sitz baths
(sitting in a few inches of warm water). If these treatments don't relieve pain,
surgery might be needed to decrease spasm in the sphincter muscle.
Perianal abscesses can occur when the tiny anal
glands that open on the inside of the anus become blocked, and the bacteria
always present in these glands cause an infection. When pus develops, an abscess
forms. Treatment includes draining the abscess, usually under local anesthesia
in the doctor's office.
An anal fistula often follows drainage of an
abscess and is an abnormal tube-like passageway from the anal canal to a hole in
the skin near the opening of the anus. Body wastes traveling through the anal
canal are diverted through this tiny channel and out through the skin, causing
itching and irritation. Fistulas also cause drainage, pain, and bleeding. They
rarely heal by themselves and usually need surgery to drain the abscess and
"close off" the fistula.
Other perianal infections
Sometimes the skin glands near the anus become infected and need
to be drained. Just behind the anus, abscesses can form that contain a small
tuft of hair at the back of the pelvis (called a pilonidal cyst).
Sexually transmitted diseases that can affect the anus include
anal warts, herpes, AIDS, chlamydia, and gonorrhea.
Diverticulosis is the presence of small outpouchings (diverticula)
in the muscular wall of the large intestine that form in weakened areas of the
bowel. They usually occur in the sigmoid colon, the high-pressure area of the
lower large intestine.
Diverticular disease is very common and occurs in 10 percent of
people over age 40 and in 50 percent of people over age 60 in Western cultures.
It is often caused by too little roughage (fiber) in the diet. Diverticulosis
rarely causes symptoms.
Complications of diverticular disease happen in about 10 percent
of people with outpouchings. They include infection or inflammation (diverticulitis),
bleeding, and obstruction. Treatment of diverticulitis includes antibiotics,
increased fluids, and a special diet. Surgery is needed in about half the
patients who have complications to remove the involved segment of the colon.
Colon polyps and cancer
Each year 130,000 Americans are diagnosed with colorectal
cancer, the second most common form of cancer in the United States. Fortunately,
with advances in early detection and treatment, colorectal cancer is one of the
most curable forms of the disease. By using a variety of screening tests, it is
possible to prevent, detect, and treat the disease long before symptoms appear.
The importance of screening
Almost all colorectal cancers begin as polyps, benign
(non-cancerous) growths in the tissues lining the colon and rectum. Cancer
develops when these polyps grow and abnormal cells develop and start to invade
surrounding tissue. Removal of polyps can prevent the development of colorectal
cancer. Almost all precancerous polyps can be removed painlessly using a
flexible lighted tube called a colonoscope. If not caught in the early stages,
colorectal cancer can spread throughout the body. More advanced cancer requires
more complicated surgical techniques.
Most early forms of colorectal cancer do not cause symptoms,
which makes screening especially important. When symptoms do occur, the cancer
might already be quite advanced. Symptoms include blood on or mixed in with the
stool, a change in normal bowel habits, narrowing of the stool, abdominal pain,
weight loss, or constant tiredness.
Most cases of colorectal cancer are detected in one of four ways:
- By screening people at average risk for colorectal cancer beginning at
- By screening people at higher risk for colorectal cancer (for example,
those with a family history or a personal history of colon polyps or cancer)
- By investigating the bowel in patients with symptoms
- A chance finding at a routine check-up
Early detection is the best chance for a cure.
There are several types of colitis, conditions that cause an inflammation of the bowel. These include:
- Infectious colitis
- Ulcerative colitis (cause not known)
- Crohn's disease (cause not known)
- Ischemic colitis (caused by not enough blood going to the colon)
- Radiation colitis (after radiotherapy)
Colitis causes diarrhea, rectal bleeding, abdominal cramps, and urgency (frequent and
immediate need to empty the bowels). Treatment depends on the diagnosis, which is made by
colonoscopy and biopsy.
Many diseases of the colon and rectum can be prevented or
minimized by maintaining a healthy lifestyle, practicing good bowel habits, and
submitting to cancer screening.
If you have a family history of colorectal cancer or polyps, you
should have a colonoscopy beginning at age 40, or 10 years younger than your
youngest family member with cancer. (For example, if your brother was diagnosed
with colorectal cancer or polyps at age 45, you should begin screening at age
If you have no family history of colorectal cancer and no
personal history of other cancers, you should have a colonoscopy at age 50.
If you have symptoms of colorectal cancer you should consult
your doctor right away. Common symptoms include:
- A change in normal bowel habits
- Blood on or in the stool that is either bright or dark
- Unusual abdominal or gas pains
- Very narrow stool
- A feeling that the bowel has not emptied completely after passing stool
- Unexplained weight loss
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 9/8/2008…#7040