Irritable Bowel Syndrome (IBS)
What is IBS?
Irritable bowel syndrome (IBS) is a
disorder that affects your lower GI (gastrointestinal) tract. This includes the small
intestine and large intestine (colon). It is diagnosed when a person has belly pain or
spasm associated with a change in the appearance or frequency of their bowel movements.
- Belly cramps
- Swelling or bloating
- Changes in your bowel habits, such as
diarrhea or constipation
When you have IBS, your colon looks
normal. But it does not work the way it should.
Health experts have not been able
to find an exact physical cause for IBS. It is often thought that stress is one cause.
Stress may make IBS symptoms worse.
IBS is a long-term, chronic
condition. It can be painful. But it doesn’t cause lasting harm to your intestines. And
it doesn’t lead to serious disease such as cancer.
There is no link between IBS and
Crohn’s disease, ulcerative colitis, or other inflammatory bowel diseases. However,
people with inflammatory bowel disease can also have IBS.
What causes IBS?
The exact cause of IBS isn’t known.
There are many possible causes of IBS, and they differ from person to person. This means
that some people can have the same symptoms, but different causes of their IBS. Some
experts think that if you have IBS, your colon or small intestine may be more sensitive
than normal. That means it has a strong reaction to things that should not normally
When you have IBS, your colon muscles begin to move and tighten uncontrollably (spasm)
after only mild stimulation or after normal events such as:
- Swelling or bloating from gas or other material in the colon
- Some medicines
- Some foods
Women with IBS seem to have more symptoms during their periods. This could mean that
the chemicals (reproductive hormones) released during a woman’s menstrual cycle may
increase IBS symptoms.
Some things can make IBS symptoms
worse. The 2 things most likely to make your IBS symptoms worse are the foods you eat
and having emotional stress.
Diet. Eating makes your colon muscles move or contract.
This normally gives you an urge to have a bowel movement 30 to 60 minutes after a
meal. Having fat in your diet can cause contractions in your colon after a meal. With
IBS, the urge may come sooner. You may also have cramps or diarrhea. Common foods
that cause IBS are dairy products with lactose and poorly digested carbohydrates
Stress. If you have IBS, stress can make your colon move
uncontrollably or spasm. Experts don’t fully understand why. But they believe this
happens because the colon is partly controlled by the brain and spinal cord (nervous
system). The nervous system controls how your body moves and reacts to things. Going
for counseling or therapy and trying to reduce your stress can help to ease IBS
symptoms. But this doesn’t mean that IBS is caused by a mental or emotional disorder.
IBS is caused in part because of a problem with how the muscles of the colon
Who is at risk for IBS?
You are more likely to be at risk for IBS if you:
Are young. Most people first get IBS before they are 45 years
- Are a woman. Women get IBS almost twice as often as men.
- Have had recent gastroenteritis
What are the symptoms of IBS?
Each person’s symptoms may vary. Some of the most common symptoms include:
- Having belly pain
- Having painful constipation or diarrhea
- Going back and forth between having constipation and having diarrhea
- Having mucus in your stool
The symptoms of IBS may look like
other health problems. Always see your healthcare provider to be sure. IBS does not
cause rectal bleeding. Discuss any bleeding with your healthcare provider.
How is IBS diagnosed?
Your healthcare provider will look
at your past health and give you a physical exam. You may not need any specific testing.
Your provider will decide how much testing you need depending on your age and symptoms.
They will also do lab tests to check for infection and for redness and swelling
There are usually no physical signs
to tell for sure that you have IBS. There are also no exact tests for IBS.
Your healthcare provider will do lab tests and imaging tests to make sure that you
don’t have other diseases. These tests may include the following:
Blood tests. These are done to see if you are lacking
healthy red blood cells (anemia), have an infection, or have an illness caused by
inflammation or irritation.
Urinalysis and urine culture. These help to see if you
have an infection in any part of your urinary system (urinary tract infection or
UTI). This includes your kidneys, the tubes that send urine from the kidneys to the
bladder (ureters), your bladder, and the urethra, where urine leaves your body.
Stool culture. This test checks for any abnormal bacteria
or parasites in your digestive tract that may cause diarrhea and other problems. To
do this, a small stool sample is taken and sent to a lab. Other infections can also
be evaluated by a stool sample.
Stool testing for blood (fecal occult blood test). This
test checks for hidden blood in your stool that can only be seen with a microscope.
A small amount of stool is tested in a a lab. If blood is found, it may mean you
have redness and swelling (inflammation) in your GI (gastrointestinal) tract.
Upper endoscopy, also called EGD (esophagogastroduodenoscopy).
This test looks at the inside or lining of your food pipe (esophagus), stomach,
and the top part of your small intestine (duodenum). This test uses a thin, lighted
tube, called an endoscope. The tube has a camera at one end. The tube is put into
your mouth and throat. Then it goes into your esophagus, stomach, and duodenum. Your
healthcare provider can see the inside of these organs. He or she can also take a
small tissue sample (biopsy), if needed.
Abdominal X-rays. This test makes images of your internal
tissues, bones, and organs.
Abdominal ultrasound. If your symptoms seem like they may
be coming from the liver or gallbladder area, an ultrasound can check. It can also
check how blood is flowing through different blood vessels.
Colonoscopy. This test looks at the full length of your
large intestine. It can help check for any abnormal growths, red or swollen tissue
(inflammation), sores (ulcers), or bleeding. A long, flexible, lighted tube called a
colonoscope is put into your rectum up into the colon. This tube lets your healthcare
provider see the lining of your colon and take out a tissue sample (biopsy) to test
it. They may also be able to treat some problems that may be found.
Breath test. This test may diagnose bacterial overgrowth
that some believe can lead to IBS.