IBS - Irritable bowel syndrome : Description:
Alternative Names: Nervous indigestion; Spastic colon; Intestinal neurosis; Functional colitis; Irritable colon; Mucous colitis; Laxative colitis; IBS
Irritable bowel syndrome (IBS) is a somewhat baffling yet common intestinal disorder that affects the colon (the large intestine). The colon's main function is to absorb water and nutrients from partially digested food. Anything that is not absorbed is slowly moved through the colon toward the rectum and out of the body as waste in the form of feces (also called stool).
Muscles in the colon work to get rid of the body's waste products by contracting and relaxing as they push the undigested food through the large intestine. These muscles must also work together with other muscles in the body to push the waste out of the anus. If the muscles in the colon don't work at the right speed for proper digestion or if the coordination with muscles in the rectum or pelvis is somehow interrupted, the contents of the colon are not able to move along smoothly. When this happens, a person can feel the abdominal cramps, bloating, constipation, and diarrhea that may be signs of IBS.
Irritable bowel syndrome (IBS) is one of the most common ailments of the bowel (intestines) and affects an estimated 15% of persons in the US. The term, irritable bowel, is not a particularly accurate one since it implies that the bowel is responding irritably to normal stimuli, and this may or may not be the case. The several names for IBS, including spastic colon, spastic colitis, and mucous colitis, attest to the difficulty of getting a descriptive handle on the ailment. Moreover, each of the other names is itself as problematic as the term IBS.
IBS is best described as a functional disease. The concept of functional disease is particularly useful when discussing diseases of the gastrointestinal tract. The concept applies to the muscular organs of the gastrointestinal tract; the esophagus, stomach, small intestine, gallbladder, and colon. What is meant by the term, functional, is that either the muscles of the organs or the nerves that control the organs are not working normally, and, as a result, the organs do not function normally. The nerves that control the organs include not only the nerves that lie within the muscles of the organs but also the nerves of the spinal cord and brain to which they connect.
Symptoms range from mild to severe, however most people have mild symptoms. IBS symptoms may be worse in patients with underlying stress or mood disorders such as anxiety and depression, but it is important to understand that these conditions do not cause IBS. Symptoms may include:
The following have been associated with a worsening of IBS symptoms:
- Abdominal distention.
- Abdominal fullness, gas, bloating.
- Chronic and frequent constipation, usually accompanied by pain.
- Chronic and frequent diarrhea, usually accompanied by pain.
- Emotional distress.
- Depression Loss of appetite.
- Nausea and vomiting.
Causes and Risk factors:
Researchers have yet to discover any specific cause for IBS. One theory is that people who suffer from IBS have a colon, or large intestine, that is particularly sensitive and reactive to certain foods and stress. The immune system, which fights infection, may also be involved.
Normal motility, or movement, may not be present in the colon of a person who has IBS. It can be spasmodic or can even stop working temporarily. Spasms are sudden strong muscle contractions that come and go.
The lining of the colon called the epithelium, which is affected by the immune and nervous systems, regulates the flow of fluids in and out of the colon. In IBS, the epithelium appears to work properly. However, when the contents inside the colon move too quickly, the colon loses its ability to absorb fluids. The result is too much fluid in the stool. In other people, the movement inside the colon is too slow, which causes extra fluid to be absorbed. As a result, a person develops constipation.
A person's colon may respond strongly to stimuli such as certain foods or stress that would not bother most people.
Recent research has reported that serotonin is linked with normal gastrointestinal (GI) functioning. Serotonin is a neurotransmitter, or chemical, that delivers messages from one part of your body to another. Ninety-five percent of the serotonin in your body is located in the GI tract, and the other 5 percent is found in the brain. Cells that line the inside of the bowel work as transporters and carry the serotonin out of the GI tract. People with IBS, however, have diminished receptor activity, causing abnormal levels of serotonin to exist in the GI tract. As a result, they experience problems with bowel movement, motility, and sensation—having more sensitive pain receptors in their GI tract.
Researchers have reported that IBS may be caused by a bacterial infection in the gastrointestinal tract. Studies show that people who have had gastroenteritis sometimes develop IBS, otherwise called post-infectious IBS.
Researchers have also found very mild celiac disease in some people with symptoms similar to IBS. People with celiac disease cannot digest gluten, a substance found in wheat, rye, and barley. People with celiac disease cannot eat these foods without becoming very sick because their immune system responds by damaging the small intestine. A blood test can determine whether celiac disease may be present. (For information about celiac disease, see the NIDDK's Celiac Disease fact sheet.).
Irritable bowel syndrome (IBS) can be diagnosed based on symptoms. In most cases, only minimal tests are needed. A health professional diagnoses IBS when a person has the typical symptoms of the disorder and, if needed, tests have ruled out other possible causes.
The amount of testing that may be done depends on several factors: your age, how your symptoms come on and how severe they are, and how you respond to the initial treatment. If you get better after some initial treatment for symptoms that the health professional suspects are caused by IBS, no further tests are needed.
Tests may include:
- Large meals.
- Bloating from gas in the colon.
- Wheat, rye, barley, chocolate, milk products, or alcohol.
- Drinks with caffeine, such as coffee, tea, or colas.
- Stress, conflict, or emotional upsets.
If the diagnosis is unclear after routine tests and you have other symptoms or pain in an area of the abdomen that may indicate a different problem, further tests may be done to clarify the diagnosis. These tests may include:
- Medical history and physical examination.
- Complete blood count (CBC), which provides information about the kinds and numbers of red blood cells, white blood cells, and platelets in the blood; and sedimentation rate, which checks for inflammation in the body.
- Stool analysis, which may include testing for blood in the stool (fecal occult blood test), infection (stool culture), or parasites (ova and parasites test).
- Flexible sigmoidoscopy, which allows a health professional to look inside the lower part of the large intestine for abnormal growths (such as tumors or polyps), inflammation, bleeding, hemorrhoids, and other conditions (such as diverticulosis).
- Colonoscopy, which allows a doctor to look at the lining of the entire large intestine (rectum and colon) through a thin, flexible viewing instrument called a colonoscope. The colonoscope helps the doctor detect polyps, tumors, and areas of inflammation or bleeding.
- Upper endoscopy, which allows your doctor to look at the lining of your esophagus, stomach, and the first part of your small intestine (duodenum) through a thin, flexible viewing instrument called an endoscope. The endoscope helps your doctor look for ulcers, inflammation, tumors, infection, or bleeding.
- Upper gastrointestinal (UGI) series, which examines the upper and part of the middle portions of the digestive tract. After you swallow a "shake" made of barium and water, X-rays are taken to track the movement of the barium through the esophagus, stomach, and first part of the small intestine (duodenum) using fluoroscopy connected to a video monitor.
- Gallbladder ultrasound, which can provide a picture of the gallbladder.
- Barium enema, an X-ray examination of the large intestine (colon and rectum) or small intestine.
Irritable bowel syndrome (IBS) is a long-term (chronic) but manageable condition. Treatment will depend on the types of symptoms you have and their severity, as well as how they affect your daily life, and will likely involve changes to your lifestyle. It is important that you work closely with your health professional to create a treatment plan that will meet your needs. Learn all you can about your condition so you can effectively communicate concerns and questions to your health professional.
Initial treatment: No single type of treatment for irritable bowel syndrome works best for everyone. You and your health professional will need to work together to determine what may be triggering your symptoms. It will be necessary for you to adapt your lifestyle to best deal with your symptoms and still carry on with your daily activities. Let your health professional know if parts of your treatment are not helping your symptoms.
For some people who have IBS, certain foods may trigger symptoms. The following suggestions may help prevent or relieve some IBS symptoms:
- Avoid caffeine and alcohol.
- Limit your intake of fatty foods.
- If diarrhea is your main symptom, limit dairy products, fruit, and artificial sweeteners such as sorbitol or xylitol.
- Increasing fiber in your diet may help relieve constipation.
- Avoiding foods such as beans, cabbage, or uncooked cauliflower or broccoli can help relieve bloating or gas.
Getting regular, vigorous exercise (such as swimming, jogging, or brisk walking) may help reduce tension and make your bowels more regular.
Medications may be used along with lifestyle changes to manage symptoms of IBS. Medications for IBS may include anticholinergics for cramping, loperamide (Imodium) for diarrhea, antidepressants such as amitriptyline, or antianxiety agents such as paroxetine (Paxil).
If stress triggers your symptoms, some form of psychological therapy or stress management may help you deal more positively with stress and help prevent or reduce stress-related IBS episodes.
Medications are an important part of relieving symptoms. Your doctor may suggest fiber supplements or laxatives for constipation or medicines to decrease diarrhea, such as Lomotil or loperamide (Imodium). An antispasmodic is commonly prescribed, which helps to control colon muscle spasms and reduce abdominal pain. Antidepressants may relieve some symptoms. However, both antispasmodics and antidepressants can worsen constipation, so some doctors will also prescribe medications that relax muscles in the bladder and intestines, such as Donnapine and Librax. These medications contain a mild sedative, which can be habit forming, so they need to be used under the guidance of a physician.
A medication available specifically to treat IBS is alosetron hydrochloride (Lotronex). Lotronex has been re-approved with significant restrictions by the U.S. Food and Drug Administration (FDA) for women with severe IBS who have not responded to conventional therapy and whose primary symptom is diarrhea. However, even in these patients, Lotronex should be used with great caution because it can have serious side effects such as severe constipation or decreased blood flow to the colon.
With any medication, even over-the-counter medications such as laxatives and fiber supplements, it is important to follow your doctor's instructions. Some people report a worsening in abdominal bloating and gas from increased fiber intake, and laxatives can be habit forming if they are used too frequently.
Medications affect people differently, and no one medication or combination of medications will work for everyone with IBS. You will need to work with your doctor to find the best combination of medicine, diet, counseling, and support to control your symptoms.
Psychological treatments: Psychological treatments include cognitive-behavioral therapy, hypnosis, psychodynamic or interpersonal psychotherapy, and relaxation/stress management. They have been used in patients with IBS who are psychologically distressed to the point that their quality of life is being impaired. A few studies have shown that psychological treatments can reduce anxiety and other psychological symptoms in addition to reducing IBS symptoms, particularly pain and diarrhea.
Diet: It is unclear if diet has much effect on the symptoms of IBS. Nevertheless, patients often associate their symptoms with specific foods (such as salads, fats, etc.). Although specific foods might worsen IBS, it is clear that they are not the cause of IBS. The common placebo response in IBS also may explain the improvement of symptoms in some people with the elimination of specific foods.
Dietary fiber often is recommended for patients with IBS. Fiber probably is of benefit to IBS patients with constipation, but it does not reduce abdominal pain.
Treatment if the condition gets worse: If your symptoms get worse, your health professional will likely conduct more tests to determine whether there is another cause for your symptoms. Irritable bowel syndrome (IBS) does not lead to more serious conditions, such as cancer or inflammatory bowel disease, but a person with IBS may also have one of these illnesses. Your health professional may also want you to try different medications, or different dosages of your current medications, if your symptoms are not responding to treatment.
Medicine and medications:
For some people with severe IBS, doctors may suggest one of several prescription or over-the-counter medications. Depending on a person's symptoms, doctors may recommend over-the-counter laxatives (for constipation) or anti-diarrhea medications, or a doctor may prescribe muscle relaxers (for colon muscle spasm) or antidepressants (for anxiety and stress). Before trying any over-the-counter medicines, it's a good idea to talk to your doctor first to be sure you get the best one for you.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.