All About IBS: An Overview

What is IBS?

Irritable bowel syndrome (IBS) is a functional disturbance of the colon. It is characterized by abdominal pain or discomfort associated with an abnormal bowel pattern in the absence of pathologic findings.
Some patients with IBS have diarrhea as their bowel disturbance, some have constipation, and some alternate between the two. IBS patients may have emotional issues that affect their symptoms. Conversely, their symptoms may affect their emotions.
It is important for a patient who may have IBS to see a physician who is capable of making sure they are not suffering from organic disease. Usually this can be done with a careful selection of appropriate tests.

IBS is the most common gastrointestinal disorder seen by both gastroenterologists and primary care physicians.
About 15% of the population has IBS, and approximately 50% of IBS sufferers see a physician because of their symptoms.
IBS affects two to three times as many women as men, most of them in the 20 to 50 age range.

The cause of IBS is not known, and the colon is anatomically normal in IBS patients. IBS physiology is characterized by a heightened sensitivity of the nerves in the lining of the colon which causes abdominal pain and abnormal muscular activity of the colon (muscular activity is increased in diarrhea and decreased in constipation).
There is no link between IBS and colon cancer or any other serious disease. Thus, IBS is not life threatening but is certainly life disrupting.

Patients with IBS may experience psychological distress, particularly forms of anxiety and depression. It appears that psychological distress is a result of dealing with a difficult syndrome, and it also plays an important role in how successfully patients cope with IBS.
Patients with IBS who visit primary care physicians and gastroenterologists tend to have a higher degree of anxiety and depression than people without IBS, but probably not more than patients with other chronic diseases. Abdominal pain is the main reason that IBS patients visit a specialist.
Since several forms of psychological treatment have been somewhat successful in alleviating IBS symptoms, it seems clear that psychological factors are important. However, each patient must individually explore the influence of psychological history, family and social relationships, and coping styles.

A number of foods can produce symptoms that are similar to IBS.
Lactose is the sugar in all dairy products. Many people have lactose intolerance which can lead to gas, bloating, abdominal pain, and diarrhea — just like IBS. A reliable office test for lactose intolerance is available, measuring hydrogen in the breath after a lactose challenge. Another method is avoiding lactose and observing the effect. If improvement is dramatic, then lactose intolerance is likely.
Sorbitol, present in sugarless gum or mints, and fructose, a sweetener in juices and iced tea, may produce similar symptoms. In some patients, other foods may be the culprit and patients should be active investigators of their own patterns.
In general, IBS symptoms vary from day to day and it is often difficult to judge the effect of dietary restriction. A healthy diet with avoidance of fried food, alcohol, chocolate, or excessive caffeine may also help. However, patients should be wary of being on too restrictive a diet since their overall nutrition may suffer.

IBS is generally divided into three main categories: mild, moderate, and severe. At least 50% of patients are mild, have infrequent symptoms, fairly normal life functioning, no significant psychological difficulties, and can manage by themselves or with the help of primary care physicians.
The majority of the remaining 50% of patients have moderate IBS: they may have intense, frequent symptoms and often require the care of a gastroenterologist and psychologist informed about IBS. Various medical treatments such as stool expanders like Metamucil and Citrucel, anti-diarrheal medication such as Imodium or Lomotil, or anti-spasmodics may be helpful for this group.
Finally, about 5% of IBS patients are in a severe group who benefit less from medical and psychological treatment. This group will sometimes respond to psychotropic medications.

It should be emphasized that most patients cope with IBS and may not even visit a physician to obtain relief. However, there are a number of studies of chronic IBS patients showing that they may experience psychological distress. The two most common diagnoses are anxiety and depression; some patients may suffer from panic disorder.
A past history of sexual and physical abuse has been reported in some IBS patients. The percentage appears to be relatively low in patients with mild symptoms and increases along with the severity of the IBS, though this area of research is still controversial and an abuse history in IBS is not more common than in other chronic illnesses.

The two ends of the brain-gut connection are the cerebral cortex and the enteric nervous system, sometimes known as the big brain and the little brain. They are connected via nerves that go back and forth and via hormones, chemicals that circulate in the blood stream.
Part of the brain, the cortex, tells us where pain is coming from and how intense it is. Another part of the brain called the limbic system controls the emotional reaction to pain.
With special brain imaging techniques, it has been shown that patients with IBS light up the emotional part of the brain when they feel pain much more than people without IBS. It has also been shown that stress causes chemical changes in the lining of the colon that increase IBS symptoms.

A number of studies have shown that IBS patients have a limited tolerance to distension of a balloon inserted into the colon, similar to a feeling they may have if gas distends the colon.
In one interesting experiment, balloon distension of the small intestine in IBS patients caused pain. However, if the patients were mentally distracted during the balloon distension, they did not feel pain. This illustrates the benefit of distraction, whether it be exercise, relaxation, or meditation.
In addition to pain sensation, motility of the colon has been measured. IBS patients have an abnormal muscular response to a number of stimuli including stress and eating a fatty meal. This is important in terms of diarrhea and constipation patterns in IBS.

IBS is considered a psychosomatic condition. A number of studies in the medical literature have documented improvement in symptoms of IBS patients treated in short-term psychotherapy (psychodynamic, cognitive-behavioral, or hypnotherapy) with therapists who are well-informed about IBS. Interestingly, improvement has been demonstrated in both gastrointestinal and psychological status of the patients. In most of these studies, there were follow-up evaluations after appropriate intervals and patients enjoyed sustained benefit.
While low dose anti-depressants may also help IBS patients, research studies show that therapy is a superior treatment approach — not because anti-depressants don't work, but because so many patients stop taking the medication.
Therapy should be IBS-focused and deal with the following questions:
- What are the patient's anxieties and fears about having IBS?
- Are there psychological events which occur prior to symptom flare-ups?
- How does IBS affect relationships and how do relationships affect IBS?
- What are the patient's coping strengths?