is Irritable Bowel Syndrome?
Irritable bowel syndrome (IBS) is
a common digestive disorder which can cause troublesome and persistent
symptoms. These vary greatly from person to person, but usually
include cramping discomfort, a feeling of fullness or bloating,
and a change or disruption of bowel habit. This can range from constipation
(difficult or infrequent passage of a motion) to diarrhea (frequent
or loose motions and an urgent need to go), or can alternate between
The symptoms appear to be due to
an increased sensitivity of the bowel, which results in spasm of
the bowel muscle. IBS is a disorder of the way in which the bowel
functions. For this reason, it is sometimes referred to as a ‘functional
The irritable bowel syndrome is
- hereditary, although other members
of the family may have similar symptoms;
- food allergy, although some patients
find they are intolerant of particular foods;
- "all in the mind", even
though test results may be normal;
- an infection, although it may
have been triggered by an initial attack of gastro-enteritis;
- bowel inflammation, as in the
case of ulcerative colitis or Crohn’s disease;
- caused by ulcers, gallstones,
cancer or other more serious digestive diseases, although some
patients with these conditions may have some symptoms in common
with IBS at some stage.
The irritable bowel
syndrome is extremely common in developed countries. More than half
of all patients attending gastroenterology out-patient clinics have
IBS. A third of people in Britain have occasional symptoms of IBS,
and 1 in 10 have symptoms bad enough to require medical attention.
Women tend to seek medical attention for it more often than men,
but the prevalence in men and women is similar. IBS commonly starts
between 15 and 40 years of age, but may occur at any age.
are the symptoms of IBS?
The symptoms differ between patients
and may vary from time to time, but all patients will have at least
some of these:
- Abdominal pain, which is often
colicky in nature. It may be felt anywhere in the abdomen, but
is often low down on the left. Many patients find their pain is
worse when constipated, and it may be relieved by opening the
bowels or passing flatus (wind from the back passage). In women
there may be a pattern associated with their periods.
- Fullness and bloating, making
clothes feel tight and uncomfortable and sometimes associated
with rumbling noises and flatulence (wind). The abdomen may feel
tender. Belching and passing wind through the back passage can
ease this. Nausea can occur but vomiting is not usually a feature
- Alteration in bowel habit, which
may be constipation, diarrhea or an alternation between the two.
Bowel habit varies enormously between individuals, though most
people have their own pattern. The change in bowel habit may be
in the frequency of action, the form of the motions, or associated
urgency (rushing to go). There may be some discomfort or difficulty
in opening the bowels. A sensation of incomplete emptying is common.
Ineffectual straining to pass a motion (tenesmus) and a sharp
pain felt low down inside the back passage (proctalgia fugax)
are also common. Incontinence can occasionally occur, causing
great embarrassment and anxiety.
Though some of these symptoms may
be embarrassing or distressing, it is important to tell the doctor
about them. Worrying in silence may make them feel even worse. Remember,
they happen to a lot of people.
| What is the cause
of irritable bowel syndrome?
The cause of IBS is not fully
understood yet. Research has shown that the bowel in IBS sufferers
is more sensitive than usual and this sensitivity sets off a reaction
which causes the symptoms. Understanding the normal muscle control
in the bowel helps to explain what happens in IBS.
The bowel is a muscular tube which
propels food from mouth to anus, allowing nutrients to be digested
and absorbed along the way. The colon (large bowel) links the small
bowel to the rectum and anus (back passage), and is the source of
most of the symptoms of IBS. It acts as a reservoir for the semi-liquid
residue of the digestion of food, and absorbs water and salts from
this, leaving a more formed motion to be passed. Regular muscular
contractions propel the contents through the colon. If the bowel
is overactive, the contents pass more rapidly and the patient gets
diarrhoea, whereas sluggish activity causes constipation. Muscle
spasm in the bowel causes discomfort and cramping pain. Eating a
meal, or the presence of gas in the bowel, can trigger contraction
and spasm, causing symptoms.
Anxiety, depression and stress related
pressures of life are commonly associated with IBS. Feeling low
may occur as a result of distressing bowel symptoms, but in some
it occurs spontaneously and seems to aggravate the problem. Symptoms
of IBS may increase stress because of fears that there is some serious
The nature of the diet, eating habits
and lifestyle also influence the way the bowel functions. Too much,
or too little, dietary fibre; too much fat; or a very rich or spicy
diet may all upset the working of the bowel and trigger the symptoms
Alcohol, coffee, tea and smoking
can all act as stimulants to the bowel and provoke an attack. For
some people, certain foods may have the same effect. However, often
there is no obvious precipitating factor.
any investigations necessary?
Investigations are important to exclude
other more serious bowel disorders that can produce similar symptoms
to those of IBS. The history of the symptoms and a physical examination
will help to establish the diagnosis. In many young patients, the
doctor may diagnose with a few initial investigations and treat
the disorder. In older patients who develop new digestive symptoms,
the doctor will do more extensive investigations to exclude other
bowel disorders. Laboratory tests, x-rays and endoscopy (internal
examination with an instrument) may be done to exclude other digestive
disease. The response to a trial of treatment may help to establish
the diagnosis. If some of the symptoms are not typical, such as
weight loss or blood in the motions, full investigation is essential.
treatment is available?
Although the irritable bowel syndrome
may produce troublesome symptoms, it does not lead to serious complications.
It is important to know and understand this. An explanation of the
disorder and how symptoms are produced helps to relieve anxiety
and allows the patient to cope better with the symptoms. If attacks
are infrequent or mild, this insight may be sufficient. Reassurance
that more serious or progressive disorders are not present is also
important. A knowledge of what provokes an attack may help individuals
control their symptoms more effectively and prevent attacks, or
at least help them to cope better.
Advice on diet, eating habits and
lifestyle helps many IBS sufferers. A well-balanced ‘healthy’ diet,
taken as regular meals, will reduce symptoms. Some patients benefit
from increasing the fibre content of the diet and others may be
helped by reduction in fibre intake. Important foods containing
fibre are cereals, fruit and vegetables. Fibre supplements prepared
from plants can be prescribed or obtained from the chemist, but
these should not be used without first discussing the symptoms with
Foods which are high in fat often
provoke symptoms and should be avoided. Rich or spicy foods can
also cause attacks. People usually are aware of particular foods
which upset them, but may not associate attacks with common foods
such as dairy products, bread and cereals, which can trigger symptoms.
Large, infrequent meals challenge the digestion much more than small,
frequent ones, which often help to reduce symptoms.
Patients who relate their symptoms
to stress or anxiety usually benefit from a better understanding
of the condition. Sometimes counseling in stress management is helpful.
Others with more severe symptoms may benefit from hypnotherapy.
If anxiety or depression are a major part of the problem, psychotherapy
may help. Treatment with an antidepressant may also reduce symptoms.
Antispasmodic drugs help some patients,
but response is variable. Constipation may require additional laxative
treatment under medical supervision. Diarrhea can also be controlled,
particularly if it is limiting activity, mobility and lifestyle.
In many cases, reassurance, explanation
and symptomatic treatment are all that is required and regular medication
is not necessary.
Read also: What
medication is there for IBS?.
Despite considerable research, the
cause of irritable bowel syndrome remains in-completely understood
and there is, as yet, no cure. It is well established that the symptoms
of IBS are due to the way in which the bowel functions, rather than
any specific disease of the bowel. With new research methods, which
the Digestive Disorders Foundation is supporting, it is becoming
possible to monitor the functioning of the bowel and to understand
it better. It is hoped that this will provide more specific and
effective treatments for the troublesome symptoms of this common
condition. Fortunately, most patients’ symptoms are reasonably controlled
most of the time by the treatments outlined. For some, the symptoms
often resolve on their own with time. However, there is a continuing
need to sustain further research into IBS, to help relieve the symptoms
for sufferers and to advance our understanding of the functioning
of the bowel.
questions? Ask here.