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Irritable Bowel Syndrome

National Digestive Diseases Information Clearinghouse

What is irritable bowel IBS is often classified into four subtypes based on a person’s usual stool consistency. syndrome (IBS)? These subtypes are important because they is a functional affect the types of treatment that are most U.S. Department gastrointestinal (GI) disorder, meaning it likely to improve the person’s symptoms. of Health and is a problem caused by changes in how the The four subtypes of IBS are Human Services GI tract works. People with a functional GI disorder have frequent symptoms, but the • IBS with (IBS-C) NATIONAL INSTITUTES GI tract does not become damaged. IBS is – hard or lumpy stools at least 25 per- OF HEALTH not a disease; it is a group of symptoms that cent of the time occur together. The most common symp- toms of IBS are or discom- – loose or watery stools less than fort, often reported as cramping, along with 25 percent of the time , constipation, or both. In the past, • IBS with diarrhea (IBS-D) IBS was called , mucous colitis, spas- – loose or watery stools at least tic colon, nervous colon, and spastic bowel. 25 percent of the time The name was changed to reflect the under- standing that the disorder has both physical – hard or lumpy stools less than and mental causes and is not a product of a 25 percent of the time person’s imagination. • Mixed IBS (IBS-M) IBS is diagnosed when a person has abdomi- – hard or lumpy stools at least 25 per- nal pain or discomfort at least three times cent of the time per month for the last 3 months without other disease or injury that could explain the – loose or watery stools at least pain. The pain or discomfort of IBS may 25 percent of the time occur with a change in stool frequency or • Unsubtyped IBS (IBS-U) consistency or may be relieved by a bowel movement. – hard or lumpy stools less than 25 percent of the time – loose or watery stools less than 25 percent of the time What is the GI tract? The absorbs water and any remaining nutrients from partially digested The GI tract is a series of hollow organs food passed from the . The joined in a long, twisting tube from the large intestine then changes waste from mouth to the anus. The movement of mus- liquid to a solid matter called stool. Stool cles in the GI tract, along with the release passes from the colon to the . The of hormones and enzymes, allows for the rectum is located between the last part of of food. Organs that make up the the colon—called the sigmoid colon—and GI tract are the mouth, , stom- the anus. The rectum stores stool prior to ach, small intestine, large intestine—which a bowel movement. During a bowel move- includes the , cecum, colon, and ment, stool moves from the rectum to the rectum—and anus. The intestines are some- anus, the opening through which stool leaves times called the bowel. The last part of the the body. GI tract—called the lower GI tract—consists of the large intestine and anus.

Transverse colon

Ascending Descending colon colon

Sigmoid colon Cecum

Anus Rectum

The lower GI tract

2 Irritable Bowel Syndrome How common is IBS and • feeling that a bowel movement is who is affected? incomplete Irritable bowel syndrome is estimated to • passing mucus, a clear liquid made by affect 3 to 20 percent of the population, with the intestines that coats and protects most studies ranging from 10 to 15 percent.1 tissues in the GI tract However, less than one-third of people with • abdominal the condition see a health care provider for Symptoms may often occur after eating a diagnosis.2 IBS affects about twice as many meal. To meet the definition of IBS, symp- women as men and is most often found in toms must occur at least 3 days a month. people younger than 45 years.1

What are the symptoms of What causes IBS? The causes of IBS are not well understood. IBS? Researchers believe a combination of physi- The symptoms of IBS include abdominal cal and mental health problems can lead to pain or discomfort and changes in bowel IBS. The possible causes of IBS include the habits. To meet the definition of IBS, the following: pain or discomfort should be associated with two of the following three symptoms: • Brain-gut signal problems. Signals between the brain and nerves of the • start with bowel movements that occur small and large intestines, also called more or less often than usual the gut, control how the intestines work. • start with stool that appears looser and Problems with brain-gut signals may more watery or harder and more lumpy cause IBS symptoms, such as changes in than usual bowel habits and pain or discomfort. • improve with a bowel movement • GI motor problems. Normal motil- ity, or movement, may not be present Other symptoms of IBS may include in the colon of a person who has IBS. • diarrhea—having loose, watery stools Slow can lead to constipation three or more times a day and feeling and fast motility can lead to diarrhea. urgency to have a bowel movement Spasms, or sudden strong muscle con- tractions that come and go, can cause • constipation—having hard, dry stools; abdominal pain. Some people with IBS three or fewer bowel movements in also experience hyperreactivity, which a week; or straining to have a bowel is an excessive increase in contractions movement of the bowel in response to or eating.

1Grundmann O, Yoon SL. Irritable bowel syndrome: epidemiology, diagnosis, and treatment: an update for health-care practitioners. Journal of and . 2010;25:691–699. 2Owyang C. Irritable bowel syndrome. In: Yamada T, ed. Textbook of Gastroenterology. 5th ed. Vol. 1. West Sussex, UK: John Wiley & Sons Ltd.; 2009: 1536–1573. 3 Irritable Bowel Syndrome • Hypersensitivity. People with IBS have studies have shown to be a lower pain threshold to stretching of effective in treating IBS. However, the the bowel caused by gas or stool com- studies were weak and more research pared with people who do not have IBS. is needed to show a link between SIBO The brain may process pain signals from and IBS. the bowel differently in people with IBS. • Body chemicals. People with IBS have • Mental health problems. Mental altered levels of neurotransmitters, health, or psychological, problems such which are chemicals in the body that as panic disorder, , , transmit nerve signals, and GI hor- and post-traumatic stress disorder are mones, though the role these chemi- common in people with IBS. The link cals play in developing IBS is unclear. between these disorders and develop- Younger women with IBS often have ment of IBS is unclear. GI disorders, more symptoms during their menstrual including IBS, are often found in people periods. Post-menopausal women have who have reported past physical or sex- fewer symptoms compared with women ual abuse. Researchers believe people who are still menstruating. These find- who have been abused tend to express ings suggest that reproductive hormones psychological stress through physical can worsen IBS problems. symptoms. • Genetics. Whether IBS has a genetic • Bacterial . Some people cause, meaning it runs in families, is who have bacterial gastroenteritis—an unclear. Studies have shown that IBS or irritation of the stomach is more common in people with fam- and intestines caused by bacteria— ily members who have a history of GI develop IBS. Researchers do not know problems. However, the cause could be why gastroenteritis leads to IBS in some environmental or the result of height- people and not others, though psycho- ened awareness of GI symptoms. logical problems and abnormalities of • Food sensitivity. Many people with IBS the lining of the GI tract may be factors. report that certain foods and bever- • Small intestinal bacterial overgrowth ages can cause symptoms, such as foods (SIBO). Normally, few bacteria live in rich in carbohydrates, spicy or fatty the small intestine. SIBO is an increase foods, , and alcohol. However, in the number of bacteria or a change in people with food sensitivity typically do the type of bacteria in the small intes- not have clinical signs of food . tine. These bacteria can produce excess Researchers have proposed that symp- gas and may also cause diarrhea and toms may result from poor absorption weight loss. Some researchers believe of sugars or bile acids, which help break that SIBO may lead to IBS, and some down fats and get rid of wastes in the body.

4 Irritable Bowel Syndrome How is IBS diagnosed? Stool tests. A is the analysis of a sample of stool. The health care provider To diagnose IBS, a health care provider will will give the person a container for catching conduct a physical exam and take a complete and storing the stool. The sample is returned medical history. The medical history will to the health care provider or a commercial include questions about symptoms, family facility and sent to a lab for analysis. The history of GI disorders, recent , health care provider may also do a rectal medications, and stressful events related to exam, sometimes during the physical exam, the onset of symptoms. For IBS to be diag- to check for blood in the stool. Stool tests nosed, the symptoms must have started at can show the presence of parasites or blood. least 6 months prior and must have occurred at least 3 days per month for the previous Lower GI series. A lower GI series is an 3 months. Further testing is not usually x-ray exam that is used to look at the large needed, though the health care provider may intestine. The test is performed at a hospi- do a blood test to screen for other problems. tal or outpatient center by a radiologist—a Additional diagnostic tests may be needed doctor who specializes in medical imaging. based on the results of the screening blood The health care provider may give the person test and for people who also have signs written bowel prep instructions to follow at such as home. The person may be asked to follow a clear liquid diet for 1 to 3 days before the • fever procedure. A or enema may be used • rectal bleeding before the test. A laxative is medication that • weight loss loosens stool and increases bowel move- ments. An enema involves flushing water or • —too few red blood cells in the laxative into the anus using a special squirt body, which prevents the body from get- bottle. ting enough oxygen For the test, the person will lie on a table • family history of colon , irritable while the radiologist inserts a flexible tube bowel disease—long-lasting disorders into the person’s anus. The large intestine is that cause irritation and ulcers, or sores, filled with barium, making signs of problems in the GI tract—or celiac disease—an with the large intestine that may be causing immune disease in which people can- the person’s symptoms show up more clearly not tolerate , a protein found in on x rays. wheat, rye, and barley, because it will damage the lining of their small intes- For several days, traces of barium in the tine and prevent absorption of nutrients large intestine cause stools to be white or light colored. Enemas and repeated bowel Additional diagnostic tests may include a movements may cause anal soreness. A stool test, lower GI series, and flexible sig- health care provider will provide specific moidoscopy or colonoscopy. Colonoscopy instructions about eating and drinking after may also be recommended for people who the test. are older than 50 to screen for colon cancer.

5 Irritable Bowel Syndrome Flexible sigmoidoscopy and colonoscopy. How is IBS treated? The tests are similar, but a colonoscopy is Though there is no cure for IBS, the symp- used to view the rectum and entire colon, toms can be treated with a combination of while a flexible sigmoidoscopy is used to view the following: just the rectum and lower colon. These tests are performed at a hospital or outpatient • changes in eating, diet, and nutrition center by a gastroenterologist—a doctor who • medications specializes in digestive diseases. For both tests, a health care provider will give written • bowel prep instructions to follow at home. • therapies for mental health problems The person may be asked to follow a clear liquid diet for 1 to 3 days before either test. Eating, Diet, and Nutrition The night before the test, the person may Large meals can cause cramping and diar- need to take a laxative. One or more enemas rhea, so eating smaller meals more often, may also be required the night before and or eating smaller portions, may help IBS about 2 hours before the test. symptoms. Eating meals that are low in fat In most cases, light anesthesia, and possibly and high in carbohydrates, such as pasta, pain medication, helps people relax. For rice, whole-grain breads and cereals, fruits, either test, the person will lie on a table while and vegetables, may help. the gastroenterologist inserts a flexible tube Certain foods and drinks may cause IBS into the anus. A small camera on the tube symptoms in some people, such as sends a video image of the intestinal lining to a computer screen. The test can show signs • foods high in fat of problems in the lower GI tract. • milk products The gastroenterologist may also perform a • drinks with alcohol or caffeine , a procedure that involves taking a piece of intestinal lining for examination with • drinks with large amounts of artificial a microscope. You will not feel the biopsy. sweeteners, which are substances used A pathologist—a doctor who specializes in in place of sugar diagnosing diseases—examines the tissue in • foods that may cause gas, such as beans a lab. and cabbage Cramping or bloating may occur during People with IBS may want to limit or avoid the first hour after the test. Driving is not these foods. Keeping a food diary is a good permitted for 24 hours after a colonos- way to track which foods cause symptoms so copy to allow the sedative time to wear off. they can be excluded from or reduced in the Before the appointment, a person should diet. make plans for a ride home. Full recovery is expected by the next day.

6 Irritable Bowel Syndrome may lessen constipation in reduces stool frequency people with IBS, but it may not help with and improves stool consistency by slow- lowering pain. Fiber helps keep stool soft so ing the movement of stool through the it moves smoothly through the colon. The colon. Academy of Nutrition and Dietetics recom- • . Antispasmodics, such mends consuming 20 to 35 grams of fiber as hyoscine, cimetropium, and pinave- a day for adults.3 Fiber may cause gas and rium, help to control colon muscle trigger symptoms in some people with IBS. spasms and reduce abdominal pain. Increasing fiber intake by 2 to 3 grams per day may help reduce the risk of increased gas • . Tricyclic antidepres- and bloating. sants (TCAs) and selective serotonin reuptake inhibitors (SSRIs) in low doses Medications can help relieve IBS symptoms includ- The health care provider will select medica- ing abdominal pain. In theory, TCAs tions based on the person’s symptoms. should be better for people with IBS-D and SSRIs should be better for people • Fiber supplements. Fiber supplements with IBS-C due to the effect on colon may be recommended to relieve consti- transit, but this has not been confirmed pation when increasing dietary fiber is in clinical studies. TCAs work in people ineffective. with IBS by reducing sensitivity to pain • . Constipation can be treated in the GI tract as well as normalizing GI with laxative medications. Laxatives motility and secretion. work in different ways, and a health care • (Amitiza). Lubipros- provider can provide information about tone is prescribed for people who have which type is best for each person. IBS-C. The medication has been found More information about different types to improve symptoms of abdominal pain of laxatives can be found in the National or discomfort, stool consistency, strain- Digestive Diseases Information Clear- ing, and constipation severity. inghouse (NDDIC) fact sheet Constipa- tion at www.digestive.niddk.nih.gov. The can reduce abdomi- nal bloating by treating SIBO. But scientists • Antidiarrheals. Loperamide has been are still debating the use of antibiotics to found to reduce diarrhea in people treat IBS, and more research is needed. with IBS, though it does not reduce pain, bloating, or other symptoms.

3Slavin, JL. Position of the American Dietetic Association: health implications of dietary fiber. Journal of the American Dietetic Association. 2008;108:1716–1731. 7 Irritable Bowel Syndrome Probiotics • . In hypnotherapy, the Probiotics are live microorganisms, usually therapist uses to help the per- bacteria, that are similar to microorganisms son relax into a trancelike state. This normally found in the GI tract. Studies have type of therapy may help the person found that probiotics, specifically Bifidobac- relax the muscles in the colon. teria and certain combinations, • Mindfulness training. People practic- improve symptoms of IBS when taken in ing this type of are taught large enough amounts. But more research is to focus their attention on sensations needed. Probiotics can be found in dietary occurring at the moment and to avoid supplements, such as capsules, tablets, and worrying about the meaning of those powders, and in some foods, such as . sensations, also called catastrophizing. A health care provider can give information about the right kind and right amount of What other conditions are probiotics to take to improve IBS symptoms. More information about probiotics can be associated with IBS? found in the National Center for Comple- People with IBS often suffer from other mentary and Alternative Medicine fact sheet GI and non-GI conditions. GI conditions An Introduction to Probiotics at www.nccam. such as gastroesophageal reflux disease nih.gov/health/probiotics/introduction.htm. (GERD) and dyspepsia are more common in people with IBS than the general popula- Therapies for Mental Health tion. GERD is a condition in which stomach Problems contents flow back up into the esophagus— The following therapies can help improve the organ that connects the mouth to the IBS symptoms due to mental health stomach—because the muscle between problems: the esophagus and the stomach is weak or relaxes when it should not. Dyspepsia, or • Talk therapy. Talking with a therapist , is upper abdominal discomfort may reduce stress and improve IBS that often occurs after eating. Dyspepsia symptoms. Two types of talk therapy may be accompanied by fullness, bloating, used to treat IBS are cognitive behav- , or other GI symptoms. More infor- ioral therapy and psychodynamic, or mation about these conditions can be found interpersonal, therapy. Cognitive in the NDDIC fact sheets , Gastro- behavioral therapy focuses on the esophageal Reflux (GER), and Gastroesopha- person’s thoughts and actions. Psycho- geal Reflux Disease (GERD) and Indigestion dynamic therapy focuses on how emo- at www.digestive.niddk.nih.gov. tions affect IBS symptoms. This type of therapy often involves relaxation and stress management techniques.

8 Irritable Bowel Syndrome Non-GI conditions often found in people Points to Remember with IBS include • Irritable bowel syndrome (IBS) is a • chronic syndrome—a disorder functional gastrointestinal (GI) disor- that causes extreme fatigue, which is der, meaning it is a problem caused by tiredness that lasts a long time and lim- changes in how the GI tract works. Peo- its a person’s ability to do ordinary daily ple with a functional GI disorder have activities frequent symptoms, but the GI tract does not become damaged. • chronic • IBS is not a disease; it is a group of • temporomandibular joint disorders— symptoms that occur together. problems or symptoms of the chewing muscles and joints that connect the • IBS is estimated to affect 3 to 20 per- lower jaw to the skull cent of the population, with most studies ranging from 10 to 15 percent. • depression However, less than one-third of people • anxiety with the condition see a health care • somatoform disorders—chronic pain or provider for diagnosis. other symptoms with no physical cause • The symptoms of IBS include abdomi- that are thought to be due to psycho- nal pain or discomfort and changes in logical problems bowel habits. Other symptoms of IBS may include How does stress affect IBS? – diarrhea Stress can stimulate colon spasms in people – constipation with IBS. The colon has many nerves that connect it to the brain. These nerves con- – feeling that a bowel movement is trol the normal contractions of the colon incomplete and cause abdominal discomfort at stressful – passing mucus times. In people with IBS, the colon can be overly responsive to even slight conflict or – abdominal bloating stress. Stress makes the mind more aware • The causes of IBS are not well under- of the sensations that arise in the colon. IBS stood. Researchers believe a combi- symptoms can also increase a person’s stress nation of physical and mental health level. Some options for managing stress problems can lead to IBS. include • To diagnose IBS, a health care provider • participating in stress reduction and will conduct a physical exam and take a relaxation therapies such as meditation complete medical history. The medi- • getting counseling and support cal history will include questions about symptoms, family history of GI disor- • taking part in regular exercise such as ders, recent infections, medications, and walking or yoga stressful events related to the onset of • minimizing stressful life situations as symptoms. much as possible • getting enough sleep

9 Irritable Bowel Syndrome • Though there is no cure for IBS, the Safety Study of Probiotics in Adults with symptoms can be treated with a combi- Irritable Bowel Syndrome, funded under nation of the following: NIH clinical trial number NCT00971711, is a phase I study of the safety and effectiveness – changes in eating, diet, and nutrition of VSL#3 in adults with IBS. VSL#3 is a – medications high-potency probiotic medical food that is – probiotics commercially available. /Moxi- bustion for Irritable Bowel Syndrome (Acu/ – therapies for mental health problems MoxalIBS), funded under NIH clinical trial number NCT00945074, tests the efficacy of Hope through Research acupuncture in combination with moxibus- The National Institute of and tion for symptom improvement in adults Digestive and Kidney Diseases (NIDDK) with IBS. Moxibustion is the application of conducts and supports research into many heat from a burning herb at the acupuncture kinds of digestive disorders, including IBS. point. All participants will receive moxibus- The NIDDK and other components of the tion and will be assigned to one of three National Institutes of Health (NIH) are con- treatment protocols: standard acupunc- ducting clinical trials aimed at improving the ture, individualized acupuncture, and sham diagnosis and treatment of IBS. Self Admin- acupuncture. istered Cognitive Behavior Therapy for Irri- Participants in clinical trials can play a more table Bowel Syndrome, funded under NIH active role in their own health care, gain clinical trial number NCT00738920, assesses access to new research treatments before the short- and long-term efficacy of cognitive they are widely available, and help others behavior therapy for IBS using two treatment by contributing to medical research. For delivery systems: self-administered and ther- information about current studies, visit apist administered. Long-term project goals www.ClinicalTrials.gov. include development of an effective self- administered behavioral treatment program that can enhance quality of patient care, improve clinical outcomes, and decrease the economic and personal costs of IBS.

10 Irritable Bowel Syndrome For More Information You may also find additional information about this American Neurogastroenterology and topic by visiting MedlinePlus at www.medlineplus.gov. This publication may contain information about Motility Society medications. When prepared, this publication 45685 Harmony Lane included the most current information available. Belleville, MI 48111 For updates or for questions about any medications, contact the U.S. Food and Drug Administration toll- Phone: 734–699–1130 free at 1–888–INFO–FDA (1–888–463–6332) or visit Fax: 734–699–1136 www.fda.gov. Consult your health care provider for Email: [email protected] more information. Internet: www.motilitysociety.org International Foundation for Functional Gastrointestinal Disorders The U.S. Government does not endorse or favor any specific commercial product or company. Trade, P.O. Box 170864 proprietary, or company names appearing in this Milwaukee, WI 53217–8076 document are used only because they are considered Phone: 1–888–964–2001 or 414–964–1799 necessary in the context of the information provided. If a product is not mentioned, the omission does not Fax: 414–964–7176 mean or imply that the product is unsatisfactory. Email: [email protected] Internet: www.iffgd.org Rome Foundation P.O. Box 6524 Raleigh, NC 27628 Phone: 919–345–3927 Fax: 919–900–7646 Email: [email protected] Internet: www.romecriteria.org

Acknowledgments Publications produced by the Clearinghouse are carefully reviewed by both NIDDK scientists and outside experts. This publica- tion was reviewed by William E. Whitehead, Ph.D., University of North Carolina Center for Functional GI and Motility Disorders.

11 Irritable Bowel Syndrome National Digestive Diseases Information Clearinghouse 2 Information Way Bethesda, MD 20892–3570 Phone: 1–800–891–5389 TTY: 1–866–569–1162 Fax: 703–738–4929 Email: [email protected] Internet: www.digestive.niddk.nih.gov The National Digestive Diseases Information Clearinghouse (NDDIC) is a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). The NIDDK is part of the National Institutes of Health of the U.S. Department of Health and Human Services. Established in 1980, the Clearinghouse provides information about digestive diseases to people with digestive disorders and to their families, health care professionals, and the public. The NDDIC answers inquiries, develops and distributes publications, and works closely with professional and patient organizations and Government agencies to coordinate resources about digestive diseases.

This publication is not copyrighted. The Clearinghouse encourages users of this publication to duplicate and distribute as many copies as desired. This publication is available at www.digestive.niddk.nih.gov.

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health

NIH Publication No. 12–693 July 2012

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