The commonest condition seen by gastroenterologists.
Normal gut moves food along the gut through muscular contractions, known as propulsion. There are also areas of hold-up, known as segmentation.

Other names for (IBS) Irritable Bowel Syndrome
Some old-fashioned names for (IBS) Irritable Bowel Syndrome are :
- irritable colon
- spastic colon
- mucous colitis.

These are misleading because (IBS) Irritable Bowel Syndrome also affects the remainder of the gut.

The combination of propulsion and segmentation is called peristalsis. You are completely unaware of it when it is working normally.

The control of peristalsis is complex. The best way to regard (IBS) Irritable Bowel Syndrome is as a loss of coordination of these muscular contractions.

There is evidence that patients with irritable bowel syndrome have increased sensitivity to stimuli arising within the gut.

As well as the intestinal symptoms, psychological factors are often involved. This is not to say these symptoms are not real (they are), but (IBS) Irritable Bowel Syndrome is often the outcome of a complex interaction between psychological and physical factors.

A gut function disorder can affect the gut anywhere from the mouth to the anus, which accounts for the diversity of symptoms seen in (IBS) Irritable Bowel Syndrome .

How common is (IBS) Irritable Bowel Syndrome? About half of all people will date the start of their symptoms to a major life event such as change of house or job and others exiting events. This suggests that there may be a psychological trigger in susceptible patients. About 10 to 20 percent of people will date the start of their symptoms to an acute gastroenteritis. In the remainder of cases, the trigger factor remains unidentified.

Abnormalities in peristalsis can often be seen in close relatives of people with (IBS) Irritable Bowel Syndrome, although without symptoms. This suggests a trigger sets off the condition in susceptible people.
Nerve-signalling chemicals, particularly serotonin, appear to have an important role.

(IBS) Irritable Bowel Syndrome and cancer

Although (IBS) Irritable Bowel Syndrome can be a distressing condition, it seldom causes bowel cancer or bowel damage.
The symptoms of (IBS) Irritable Bowel Syndrome vary and may occur at any age. They most commonly start in late teenage years or early adulthood.

(IBS) Irritable Bowel Syndrome Symptoms will depend on which parts of the gut are involved. There is often overlap between areas of the gut. Some people may experience problems in only one part of the gut, others in several. Symptoms may also vary over time.

Oesophagus
A sensation like a golf ball in the throat between meals which does not interfere with swallowing (globus).
Heartburn - burning pain often felt behind the breastbone.
Painful swallowing (odynophagia), but without hold-up of food.
Sticking of food (dysphagia) - this requires investigation.

Stomach
Non-ulcer dyspepsia .
Feeling full after small meals. This may reach the stage of not being able to finish a meal.
Abdominal bloating after meals.

Small bowel
Gurgling noises which may be loud enough to cause social embarrassment (borborygmi).
Abdominal bloating which may be so severe that women describe themselves as looking pregnant.
Generalised abdominal tenderness associated with bloating.
Abdominal bloating of both types usually subsides overnight and returns the following day.

Large bowel
Other symptoms
Headaches.
In women, abdominal pain during sex.
Passing urine more often.
Fatigue and tiredness.
Sleep disturbance.
Loss of appetite.
Nausea.
Depressive symptoms in about a third of patients.
Anxiety and stress-related symptoms, which may interact with gut symptoms.

Abdominal bloating of both types usually subsides overnight and returns the following day.

Right-sided abdominal pain, either low, or tucked up under the right ribs. Does not always get better on opening the bowels. Pain tucked up under the left ribs (splenic flexure syndrome). When the pain is bad, it may enter the left armpit. Variable and erratic bowel habits alternating from constipation to diarrhoea. Increased gastro-colic reflex. This is an awakening of the childhood reflex where food in the stomach stimulates colonic activity, resulting in the need to open the bowels. Severe, short stabbing pains in the rectum, called proctalgia fugax.