What is Irritable Bowel Syndrome? Symptoms and Treatment

irritable bowel syndrome symptoms

Irritable bowel syndrome (IBS) is a disorder that leads to abdominal pain and changes in the bowel. This syndrome is not the same as the inflammatory bowel disease (IBD).

Description and Symptoms

Irritable bowel syndrome is a disease characterized by an increased sensitivity of the gut.

It should not be confused with the more serious inflammatory bowel diseases, such as ulcerative colitis and Crohn’s disease.

The disease has varied symptoms. Some sufferers tend to be constipated, while others tend to suffer from diarrhea, while a third group alternate between symptoms of constipation and diarrhea.

Other symptoms include abdominal pain, abdominal cramps, flatulence, frequent urgent need to have a bowel movement, and frequent feeling of incomplete evacuation of the bowels.

In most cases, those who suffer from irritable bowel syndrome develop psychological problems, such as depression and anxiety.

Irritable Bowel Syndrome Causes

The cause of irritable bowel syndrome (IBS) remains unknown. It sometimes follows an acute infection of the digestive tract, such as food poisoning.

The syndrome is sometimes triggered by stress or particular foods. Lactose intolerance can be a cause.

Irritable bowel syndrome seems to be more prevalent in people who have suffered psychological trauma in childhood. The disease is more common in women than men.

It may be that the disease is caused by harmful bacteria or protozoa in the gut, although research to date has not found a definite agent.

The reasons for this syndrome are not clear. It can occur after an intestinal infection. This is called postinfectious irritable bowel syndrome. Likewise, there may be other triggers, including stress.

The intestine is connected to the brain using hormonal and nerve signals that go back and forth between that organ and the brain. These affect bowel function and symptoms.

Nerves can become more active during times of stress, which can cause the bowels to become more sensitive and compress or contract more.

This syndrome can occur at any age, but often begins in adolescence or early adulthood and is twice as common in women as in men.

Approximately 1 in 6 people in the United States have symptoms of this syndrome. This condition is the most common intestinal problem that causes patients to be referred to a gastroenterologist.


Symptoms differ from person to person and range from mild to severe.

Most people have mild symptoms. It is said that a person has this syndrome when symptoms have been present for at least three days a month for three months or more.

The main symptoms include:

  • Abdominal pain
  • Gases
  • Fullness
  • Distension
  • Changes in bowel habits

Pain and other symptoms will often be reduced or will disappear after a bowel movement. Symptoms may worsen if your stool frequency changes.

People with this syndrome can alternate between constipation and diarrhea or, for the most part, have one or other condition.

If you have this syndrome with diarrhea, you will have many loose and watery stools. You may experience an urgent need for a bowel movement, which can be difficult to control.

If you have this syndrome with constipation, you will have difficulty to defecate, as well as less frequent bowel movements.

You may need force with a bowel movement and colic. Often, nothing or only a small amount of fecal matter is removed.

Symptoms may worsen for a few weeks or a month and then subside for some time. In other cases, symptoms are present most of the time.

You may also have a lack of appetite if you have this syndrome. However, the presence of blood in the stool and involuntary weight loss are not part of the syndrome in most cases.


Diet Changes: Changes in diet can help combat the disease. If it is merely a matter of removing lactose-intolerance, milk and other milk products from the everyday diet.

A high fiber diet has been proposed, but research suggests that only soluble fiber, such as that from oats, bananas, apples, carrots, potatoes, and psyllium seed husks, actually helps.

Insoluble fiber, such as that from bran and most nuts, would likely make symptoms worse.

A “low FODMAPS” diet can be used to combat the symptoms of irritable bowel syndrome. FODMAPS are fermentable oligo, di, monosaccharides and polyols.

In practice, many foods need to be excluded from such a diet, including wheat, barley, rye, onions, garlic, pulses, apples, pears, peaches, plums, blackberries, mushrooms, cauliflower, and various additives such as mannitol and sorbitol.

Restricting the amount of caffeine and alcohol drunk often helps lessen the symptoms of the disease.

Laxatives are a useful treatment where irritable bowel syndrome is associated with constipation, but not diarrhea. Polyethylene glycol and lactulose are helpful laxatives that don’t usually irritate the bowel.

The drug lubiprostone is sometimes used. Plenty of water should be drunk when using laxatives.

Anti-Diarrhea treatments are given to patients whose disease is associated with diarrhea.

Loperamide is often used. Strong opiates, such as morphine, provide relief from diarrhea, but their use is not usually encouraged since addiction can result.

Anti-Spasmodic Drugs are used to relieve abdominal cramps. Mebeverine or peppermint oil can be used.

The latter should be purchased in capsule form so that it passes through the stomach. Anti-spasmodics should not be taken during pregnancy.

Probiotic treatments sometimes relieve the symptoms of the disease. The bacterium Bifidobacterium infantis has been shown to help reduce abdominal bloating and pain.

Rifaximin, an antibiotic that works in the gut, can help relieve bloating and flatulence.

Antidepressants sometimes help those with irritable bowel syndrome.

Tricyclic antidepressants, such as amitriptyline, or selective serotonin reuptake inhibitors (SSRIs,) such as fluoxetine (Prozac), can be used.

All these medicines have significant side-effects, so should be used with caution.

Psychological therapies, such as hypnosis and cognitive behavioral therapy, can help sufferers of irritable bowel syndrome.

Tests and exams.

There is no test to diagnose irritable bowel syndrome. Most of the time, the doctor can diagnose it based on your symptoms.

Eating a lactose-free diet for two weeks can help your doctor identify lactase deficiency.

The following tests can be done to rule out other problems:

  • Blood tests to see if you have celiac disease or a low blood count (anemia).
  • Co-cultures to see if there is an infection.
  • Your doctor may recommend a colonoscopy. During this examination, a flexible probe is inserted through the anus to examine the colon.

You may need this test if:

  • Symptoms began later in life (after the age of 50).
  • You have symptoms like weight loss or bloody stools.
  • The results of your blood tests are abnormal (for example, a low blood count).

Other disorders that can cause similar symptoms include:

  • Colon cancer (it rarely causes typical symptoms of IBS, unless symptoms such as weight loss, blood in the stool, or abnormal blood tests also occur)
  • Crohn’s disease or ulcerative colitis.