Irritable Bowel Syndrome

The irritable bowel syndrome (IBS) is a gastrointestinal disorder characterized by abdominal pain and altered bowel habits, without any identifiable organic cause.

Abdominal pain in IBS
Abdominal pain in IBS

IBS is an extremely common, accounting for about 30% of all referrals to medical gastroenterologists.

Despite presenting signs and symptoms that can be quite troublesome, irritable bowel syndrome does not cause inflammation or injury in the intestine or increases the risk of intestinal cancer.

Only a small number of people with this disease have severe signs and symptoms. Most people can control their symptoms through changes in diet, lifestyle and stress management.

In this article we explain what is irritable bowel syndrome by addressing its causes, symptoms, diagnosis and treatment options.

What is irritable bowel syndrome

The irritable bowel syndrome is a disorder of the intestines can cause frames abdominal pain, excessive gas, constipation and / or diarrhea without any recognizable abnormality justifying the occurrence of such symptoms.

The IBS is a condition in which the bowel does not work as expected, but we still do not know well the reason for this change. Several surveys over recent years have raised some hypotheses, and the more likely it is that irritable bowel syndrome is caused by multiple factors.

The walls of the intestines are coated with layers of muscles contract and relax in coordinated rhythm in order to make the progress food intake throughout the gastrointestinal tract. In the patient who has IBS, contractions can be more intense and extended than the usual, increasing the rate of gastrointestinal transit, which causes gas, cramps and diarrhea. On the other hand, the IBS can also cause a reverse situation, with weak and less frequent intestinal contractions, which causes intestinal transit becomes slow, favoring the formation of dry and hard feces, which leads to constipation.

Abnormalities in the gastrointestinal tract innervation may also play an important role in the pathogenesis of this disorder, causing pain receptors react more strongly when the bowel is filled with feces or gases. Furthermore, patients with irritable bowel syndrome may complain of a sense of increased gas, when in fact, the amount of gas produced by their intestine is similar to others. In IBS, even a small distension of the bowel wall can be a very uncomfortable event, much more than it is for the rest of the population.

The irritable bowel syndrome is a chronic disorder that lasts for years, but usually switch aggravation phase of symptoms with virtually asymptomatic phases. IBS usually appear before 35 years of age and is 2 to 3 times more common in women.

Psychological factors play an important role in both the genesis of the disease and exacerbation of seizures in many patients. There are also reports of cases develop IBS after a viral or bacterial gastroenteritis. The patient has an infectious diarrhea board, curing, but is replaced in order recurrent diarrhea boards compatible with irritable bowel syndrome.

Symptoms of irritable bowel syndrome

Patients with irritable bowel syndrome may experience a variety of symptoms, which include not only gastrointestinal complaints, but also extra-intestinal. However, it is the intestinal manifestations that characterize the disease, and abdominal pain, diarrhea and constipation the most typical triad of symptoms.

The location and intensity of pain, precipitating factors, and the relief pattern of the evacuation, the type of extraintestinal symptoms, etc. can be quite different from one patient to the other, which can make diagnosis of IBS a challenge for the physician.

Chronic abdominal pain

Abdominal pain of IBS is usually described as a cramping pain with variable intensity and periodic exacerbations. There is no typical location for pain. The most common site is the lower abdomen, especially in the lower left quadrant, however, patients with IBS may complain of pain anywhere in the abdomen.

Acute episodes of pain may be triggered by food or stress, but in many patients, the simple act of evacuating is enough to ease the pain. This pattern of pain triggered by eating and relieved by bowel movement is the common good, but is not present in all patients.

As the pain of irritable bowel syndrome is not very easy to be characterized, the most important is the doctor to recognize when the pain frame NOT seem to be of IBS, but in some organic disease of the gastrointestinal tract. For example, abdominal pain associated with unintentional weight loss or loss of appetite relevant way is not usually present in IBS. An acute pain, which gradually becomes more intense and disturb the sleep of the patient, is not usual. Similarly, abdominal pain associated with fever is a warning sign that speaks in favor of gastrointestinal infections or conditions such as appendicitis or diverticulitis.

Diarrhea and/or constipation

A typical IBS symptom is a change in bowel habits, which may present as diarrhea, constipation or a picture in which there is alternation between episodes of diarrhea and constipation.

The IBS episodes of diarrhea usually occur during the day, most often in the morning or after meals. The diarrheal evacuations are usually preceded by abdominal cramps, relieving after the end of defecation. The patient may have a sudden diarrhea framework urgently to evacuate and inability to hold the stool for long. In some cases, after the dejection, the patient may have an uncomfortable sensation of incomplete evacuation.

Except for the presence of mucous in stool, complaining that about half of the patients has diarrhea of irritable bowel syndrome usually mild, with fewer daily bowel movements and no other alarm signals. If the patient has diarrhea with blood, drops of fat, faeces with black color, vomiting or an intense diarrhea, capable including disrupt sleep at night, another diagnosis than the IBS should be considered, for example, a bacterial or viral diarrhea.


Patients with IBS may have constipation frames that last from days to months, with short intervals of diarrhea or normal intestinal function. After the acute event, the individual can remain weeks without significant changes in intestinal transit, until a new crisis to trigger.

In some patients, constipation presented as a difficulty to form a large fecal mass, causing the patient to evacuate in small quantities and feces into pellets format. A feeling of incomplete evacuation, even when the rectum is now empty, is also common.

Other gastrointestinal symptoms

Diarrhea, constipation and abdominal pain are the most typical gastrointestinal symptoms of IBS, but not the only ones. Abdominal bloating, excessive gas, gastroesophageal reflux, difficulty swallowing, early satiety, heartburn and nausea may also occur.

Extra-intestinal symptoms

Often, patients with IBS also feature extra-intestinal symptoms, including menstrual cramps, pain during sex, increased urination and symptoms of fibromyalgia.

Diagnosis of irritable bowel syndrome

Such as irritable bowel syndrome does not have an identifiable organic cause, laboratory tests or picture should be completely normal. In fact, the existence of changes in these exams is a fact that speaks against the diagnosis of IBS.

Therefore, as there is no specific complementary tests for IBS, diagnosis needs to be done through careful assessment of signs and symptoms of the patient. To facilitate and standardize the diagnosis, an international group of experts created in 1992 a set of criteria for the diagnosis of irritable bowel syndrome, called Rome criteria (not to be confused with the Rome criteria for constipation). These criteria have been updated over the years, and the last published in 2006, called "Rome III criteria for irritable bowel syndrome," is currently the most widely used.

According to the Rome III criteria, the patient needs to have IBS in the last three months have presented abdominal pain or discomfort for at least three days each month MORE 2 of the 3 following findings:
  • Improvement of abdominal pain after bowel movement.
  • Abdominal pain begins with changes in appearance of the stool.
  • Abdominal pain begins with changes in bowel habits (ie diarrhea or constipation).

After the establishment of the diagnosis, the IBS can also be classified into four subtypes, according to the characteristics of symptoms, namely:
  • Irritable bowel syndrome with constipation: hard stools or pellets by at least 25% of bowel movements / loose or watery stools in less than 25% of bowel movements.
  • Irritable Bowel Syndrome diarrhea: loose or watery stools at least 25% of evacuations / hard stools or balls within 5% of bowel movements.
  • Mixed irritable bowel syndrome: loose or watery stools at least 25% of bowel movements / hard stools or pellets by at least 25% of bowel movements
  • Nonspecific irritable bowel syndrome: Any standard that does not fit in the three definitions above.

Treatment of irritable bowel syndrome

Because the causes of irritable bowel syndrome remain unknown, current therapies focus of disease the relief of symptoms and improvement in quality of life.

In most patients with mild cases of IBS, the signs and symptoms can be easily controlled with changes in lifestyle and diet. It is important that the patient learns to recognize what types of foods trigger the crisis, so you can avoid them. Reducing stress is also a vital factor in treatment, but this is not always easy to implement. Regular exercise and frequent intake of water, the latter especially those with SSI with diarrhea, are also important.

Tips regarding diet for irritable bowel syndrome

Patients with IBS may be more sensitive to some types of carbohydrates which are fermented during the process of digestion, since this process can lead to increased gas production by intestinal bacteria. Some patients also benefit when restrict foods high in gluten.

The list of foods that can trigger diarrhea attacks, bloating or abdominal pain in irritable bowel syndrome is quite large, and not always what is bad for an individual has the same effect for another. The important thing is to know the list and try to detect what are the foods that in your particular case are less tolerated. They are: soft drinks, cabbage, broccoli, cauliflower, beans, dairy products, onions, wheat, barley, rye, leeks, garlic, chives, artichokes, beets, fennel, peas, chicory, pistachio, nuts cashews, lentils, chickpeas, apple, pear, mango, cherry, watermelon, asparagus, honey, corn syrup, apricot, nectarine, peach, plum, mushrooms and chewing gum.

Remedies for irritable bowel syndrome

In patients with moderate to severe IBS, whose symptoms affect quality of life, drug treatment is usually necessary. In this case, a query is essential gastroenterologist.

Patients in which the predominant symptom is diarrhea, antidiarrheal, such as loperamide (Imosec) may be useful. If the colic is the main symptom, antispasmodics, such as hyoscine and scopolamine help. In patients with constipation, laxatives are often required to regulate the intestinal transit.

Antidepressants can be useful in patients with depression or high levels of stress, which we know to be a factor in aggravation of the symptoms of irritable bowel syndrome.

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