DIVERTICULA
What are diverticula?
A diverticulum (if there are more than one they are known
as "diverticula") is a protrusion of the inner
lining of the intestine through the outer muscular coat
to form a small pouch with a narrow neck. The commonest
site for diverticula to develop is the lower left part of
the colon. The presence of diverticula is often referred
to as diverticulosis.
What causes diverticula to form?
Some people are born with a diverticulum, most often from
the small intestine. Most diverticula develop during later
life and are more and more common with increasing age. In
Britain over half the well population aged more than 70
years have diverticula of the large intestine. In some rural
areas of the world, particularly in Africa, diverticula
are rarely seen. This difference from Western countries
is not fully understood but is thought to be due to diet.
The colon exists to process otherwise indigestible plant
foods known as dietary fibre. In the West we eat much less
fibre than in other, primarily vegetarian, regions of the
world. If the colon has plenty of fibre to deal with, the
bulky soft contents keep the walls of the bowel apart. If
little fibre is present, the stools tend to be smaller and
harder, and they do not keep the walls of the tube-like
colon apart when the muscle in the wall of the colon contracts.
These contractions form a ring-like narrowing to mix and
push the contents along.
Closed segments occur within which pressure is high and
it is thought that this pressure pushes out the pouches.
Is the presence of diverticula harmful?
We all begin life with an appendix, which is like a diverticulum
in many ways, and we do not worry about it. In the same
way many of us have diverticula projecting from the wall
of our colon. We do not know we have them and they cause
us no trouble. However, just like the appendix, a diverticulum
can become inflamed due to infection. If this occurs, it
causes local pain, can make a person feel ill, and can be
dangerous because it may perforate or bleed. Inflammation
of one or more diverticula is called diverticulitis.
What is diverticular disease?
In most people with diverticula the intestinal muscle is
normal in appearance and thickness, but in some people it
becomes thicker than normal and it has an unusual structure
when examined under the microscope. The thickening of the
muscle narrows the colon which often becomes irregular in
outline. The reason for this change in the muscle is not
known, but it is important to realise that it is not due
to infection and may not be related to diet. The muscle
abnormality can develop when very few diverticula are present
and occasionally it occurs without any diverticula. The
combination of abnormal muscle and diverticula is known
as diverticular disease. This is confusing because diverticula
and diverticular sound the same, hence the use of the word
disease.
What are the symptoms of diverticular disease?
Symptoms are due to the muscle abnormality and consist of
pain, usually in the left lower part of the abdomen, often
abdominal distension, an irregular bowel habit with pellet-like
stools, and sometimes small quantities of blood passed with
bowel actions. These symptoms are similar to those of the
irritable bowel syndrome which is not surprising because
both disorders, at least in part, are due to abnormal muscle
function.
Is investigation necessary?
Diverticula are usually discovered when a problem such as
rectal bleeding or abdominal pain is being investigated
by X-ray (barium enema) or endoscopy (sigmoidoscopy or colonoscopy).
As diverticula are so common among older people who are
well, it is very important to be sure that they are the
cause of the problem and not something else. A diagnosis
of diverticulitis is likely when there is tenderness in
the region of the diverticula and blood tests show evidence
of inflammation somewhere in the body. The muscle abnormality
of diverticular disease is shown by increased folding of
the lining in the lower left (sigmoid) colon.
Explanation is important
Reassurance that a more serious disorder is not present
helps people not to worry about the symptoms. An explanation
of the difference between symptoms due to infection and
those due to abnormal contraction of the muscle, without
inflammation, helps people understand why one treatment
may be advised and not another.
Treatment of symptomless diverticula
If diverticula are found during tests for another problem,
for example rectal bleeding due to piles, no specific treatment
is indicated. Once they have formed, diverticula are there
to stay. It is important not to worry about them. An increase
of fibre in the diet seems sensible so that the stools are
soft and easy to pass. The following foods are high in fibre:
cereals
whole-wheat bread
fruit, vegetables and berries.
If the change in diet does not suit you then return to one
that does.
Treatment of diverticulitis
The commonest type of diverticulitis is a local area of
inflammation around the colon which is sore when pressed
and accompanied by a slight fever. If this occurs you should
see your doctor who is likely to advise an antibiotic and
possibly, a temporary liquid or low residue (low fibre)
diet.
Diverticulitis can lead to serious complications but these
are uncommon. A diverticulum can rupture causing a local
abscess or generalized infection (peritonitis) within the
abdomen. Admission to hospital as an emergency will be required
and possible urgent surgery or other procedure to allow
the infection to escape. A diverticulum can perforate into
another organ, such as the bladder. Infection of diverticula
can cause scar tissue to form in the wall of the colon which
narrows the channel through which bowel contents pass. This
may lead to obstruction and cause pain, distension, constipation
and possibly vomiting.
Occasionally, severe bleeding from a diverticulum can occur
due to rupture of a blood vessel. Blood transfusion may
be needed and, occasionally, surgery.
Treatment of diverticular disease
The pain and bloating of diverticular disease may be helped
by increasing fibre in the diet as described above, but
benefit is not invariable and some people are helped by
taking less roughage. As for irritable bowel syndrome, symptoms
may be improved by avoiding large meals, especially rich
or fatty meals. Extra bulk in the diet can be provided by
medicinal preparations containing the plant seed, ispaghula,
which can be prescribed by the doctor or bought over the
counter at the Chemist.
Since the symptoms are due mainly to over-contraction of
colonic muscle, the doctor may prescribe an antispasmodic
drug.
What is the role of surgical treatment?
Urgent surgery is needed for some complications. A temporary
opening on the abdomen (colostomy) may be needed in these
circumstances. Removal of the affected segment of bowel
may be advised for recurrent episodes of diverticulitis
or a non-urgent complication. The results of surgical treatment
for these reasons are usually good. Surgical treatment for
relief of pain due to diverticular disease, in the absence
of infection or inflammation, is advised reluctantly because
the result of operation is uncertian and some sufferers
are helped only slightly or the symptoms come back after
an interval.
The need for research:
We need to know:
why diverticula are so common in the colon in Western societies;
whether changes in life style, especially diet, by young
people would prevent their development in later life;
why some people get symptoms from diverticular but most
do not;
why in some people there is an associated abnormality of
muscle in the colon;
what leads to infection or other complication of a diverticulum;
how treatment of symptoms or complications can be improved.
Information Courtesy of:
Digestive Disorders Foundation
For Further information visit the website:
www.digestivedisorders.org.uk
Email ddf@digestivedisorders.org.uk
|
|
 |
|
