Anorectal Problems
The Rectum and Anus
Perianal Abscess/Fistula
Anal Fissure
Hemorrhoids
Prevention
The rectum and anus are the last
part of the intestinal tract. They are a lot more sophisticated
than most people give them credit for.
The
Rectum and Anus
 The rectum is located just
in front of the tailbone. It is a muscular pouch lined with
mucus-secreting tissue called mucosa .
The lower part of the rectum turns forward toward the anal
canal, or anus. This narrow passage is surrounded by layers
of circular muscles called sphincters ,
which keep it closed. It is lined with mucosa above, which
changes to skin in the lower portion.
The mucosa in the upper part of the anal
canal is loosely attached to the underlying muscles, allowing
it to move down with the stool as it passes, protecting the
delicate skin from abrasion.
Normally,
when the rectum is full of stool or gas, two things happen:
first there is a sensation of urgency, a need to move the
bowels; next, a reflex relaxes the sphincter muscles and causes
the rectum to contract.
The sphincter muscle can be voluntarily tightened at this time to prevent passage of
gas or stool, but if it is appropriate, the muscle can be
allowed to relax, and the stool or gas allowed to pass,
usually with the aid of some bearing down or grunting to
increase the pressure.
All of the common problems of the anorectal area develop
in the anal canal; they are all due to injury from the passage
of stool, and are often related to constipation (hard stools).
There are three common problems: Perianal abscess/fistula,
anal fissure, and hemorrhoids |
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 When hard stool obstructs a gland in the anus, an infection
can develop, and form an abscess. This pus collection can
grow and eventually spread between the sphincter muscles
to the skin near the anus.
When the infection is drained
(an incision made in the skin over the abscess), there is
sometimes left a connection between where the infection
started in the anal canal and the place it was drained on
the outside.
This connection is called a fistula .
 The fistula usually is a small opening next to the anus
which drains small amounts of stool, and can occasionally
become blocked and infected repeatedly.
If a fistula is
present, it can be treated with an operation in which the
passage is opened up and allowed to heal from the bottom
up. Unless there is some underlying intestinal problem,
fistulas do not usually recur.
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 Passage of a hard stool,
or sharp objects in the stool (seeds or nuts) can cause a
tear in the skin lining the anal canal. This can be very painful,
especially during a bowel movement. Severe anal pain is almost
always caused by a fissure, not hemorrhoids. Often, the fissure
will heal. However, some fissures become chronic (not healing).
This condition is made worse
by the reflex muscle spasm in the anal sphincter which is
caused by the pain. With the muscle in spasm, passage of stool
becomes difficult, and there is much more stress on the skin
than usual, which keeps the fissure open.
This condition ,
chronic anal fissure , is treated by surgically
relaxing the sphincter muscle, either by stretching it under
anesthesia, or by partially cutting the sphincter muscle (sphincterotomy).
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 Constipation and straining
at stool result in damage to the connective tissue between
the lining of the anal canal and the sphincter muscles. It
also results in dilation of the veins in this area.
The dilated veins
covered by the loosened mucosa or skin are called hemorrhoids.
They can either be internal (inside the upper
part of the anal canal) or external (outside under the skin
of the lower part of the canal). Internal hemorrhoids can
prolapse (stick out), usually after a bowel movement; sometimes
they have to be pushed back inside. They can also bleed, which
is usually painless. External hemorrhoids are visible;
they can thrombose (clot forms in the veins), which is very uncomfortable but not usually severely painful, and resolves
in two to three weeks.
Hemorrhoids usually do not
require operation unless they are severe and chronic; almost
everyone has some trouble with hemorrhoids once in a while.
If surgical treatment is necessary, it may involve ligation
with rubber bands for internal hemorrhoids, or excision
under anesthesia for severe internal or external hemorrhoids.
However, in most cases, hemorrhoids can be treated
without operation.
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Most anorectal problems can be prevented or
treated by sticking to some simple rules. The most important
things to remember are:
1. Don't wait to move your bowels. Postponing a bowel movement
when you feel the need results in constipation and the need
to strain, which causes hemorrhoids.
2. Avoid constipation; drink lots of fluid and eat fiber
(such as whole wheat or bran) every day.
3. Don't sit on the toilet longer than necessary; this causes
swelling of anal tissues. When you're finished, get off and
do your reading elsewhere.
4. If your anorectal problem flares up, don't use suppositories
or hemorrhoid preparations. The best treatment is warm sitzbaths
frequently (three or four a day), and Vaseline. Don't wipe
with toilet paper - just wash with warm water after bowel
movements. The discomfort will improve quickly, usually in
five to seven days. If it does not, see a surgeon. |
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