Diseases & Conditions > Irritable Bowel Syndrome
Medically Reviewed by Kirsten Tillisch, MD
Assistant Clinical Professor
Division of Digestive Diseases
University of California
- Overview & Diagnosis
- Treatment & Prevention
- Facts to Know & Questions to Ask
- Key Q&A
- Lifestyle Tips
- Organizations and Support
What Is It?
Irritable bowel syndrome (IBS) is a common medical disorder that is characterized by chronic abdominal discomfort or pain, bloating and changes in bowel habits.
Irritable bowel syndrome (IBS) is a common medical disorder that is characterized by chronic abdominal discomfort or pain, bloating and changes in bowel habits. The abdominal pain or cramping can be a dull ache but, for some women, it can be intolerable and without relief. It can also lead to a tired feeling and even mild depression.
Some people with IBS suffer from constipation, others from diarrhea and some experience bouts of both. Symptoms associated with IBS include bloating, passage of mucus or straining with bowel movements, a sense of incomplete evacuation after bowel movements or a sense of urgency to move the bowels.
As many as 20 percent of all U.S. adults experience symptoms of IBS, which may involve an abnormality of the contractions of the colon, as well as an increased sensitivity of the nerves in the colon. The syndrome can affect men and women of all ages, but it most often strikes younger women. The condition generally appears first in people in their 20s to 40s, and women are roughly twice as likely as men to suffer from it. Women with IBS seem to have more symptoms during their menstrual periods, suggesting that reproductive hormones may play a role in this disorder.
"Syndrome" refers to a collection of symptoms, not just one or two. IBS is considered a "functional disorder" because there is no sign of structural disease on standard medical tests. It can strike otherwise healthy people. The causes are not well understood but are likely multiple, including: biological, psychological and social factors.
Some IBS patients report that their symptoms appear to have originated shortly after a bacterial infection, such as severe gastroenteritis. Clinicians have recognized this "post-infective IBS" for many years, and there is increasing evidence that, in at least a subset of patients, infection and inflammation may play key roles in symptoms. Additionally, post-infective IBS appears to be more common in women and in people under high stress. These symptoms can last for months to years after the infection and inflammation improve.
IBS is indeed irritable, often causing a great deal of discomfort and distress. But the good news is that the syndrome does not cause permanent harm to the intestines, doesn't lead to intestinal bleeding and doesn't cause cancer or inflammatory bowel diseases (such as Crohn's disease or ulcerative colitis). Moreover, if you have IBS, you may not suffer all the time. Some people can go for weeks or months with no symptoms. Others may experience daily symptoms. Further, while IBS is often chronic, when followed after several years, about a third of people no longer have IBS.
Depression and anxiety are frequently associated with IBS, and some research indicates that the syndrome may be more common among people who had early life trauma. But psychological factors notwithstanding, the symptoms are real and have a physiological basis. While stress may aggravate IBS symptoms, other factors—particularly colon motility and sensitivity of the nerves in the colon—play an important role. (Colon motility—the contraction of intestinal muscles and movement of its contents—is controlled by nerves and hormones.)
While there is no cure for IBS, you often can control symptoms through diet, stress management and prescription drugs. IBS is rarely debilitating, but in some cases, it restricts your ability to attend school or social functions, go to work or even travel short distances.
Older names for IBS include mucous colitis, spastic colon and spastic bowel. Currently IBS may also be called functional bowel disease. IBS does not result in more serious medical problems such as colitis or cancer. If left untreated, however, the symptoms of IBS will often persist, leading to pain and discomfort.
How the Colon Works
The colon, or large intestine, is about five feet long. Its primary function is to absorb water and salts from digestive products that enter from the small intestine. About two quarts of liquid matter enter the colon from the small intestine each day; it can remain there for days until most of the fluid and salts are absorbed. The leftover matter—the stool —then passes through the colon with a pattern of movements to the left side of the colon, where it is stored until a bowel movement occurs.
Movements of the colon propel the contents slowly back and forth but mainly toward the rectum. A few times each day strong muscle contractions move down the colon pushing fecal material; some of these contractions result in a bowel movement.
Some people with IBS experience an abnormality in this muscular action. They also seem to have a colon that is more sensitive and reactive than usual. Otherwise ordinary events (such as eating and distension from gas or other material in the colon) can cause the colon to overreact. Certain medicines and foods, such as chocolate, high-fat foods, milk products or large amounts of alcohol, may trigger attacks. Caffeine can cause loose stools even in some people without the condition, and it is particularly problematic for some people with IBS.
Irritable bowel syndrome (IBS) is a common medical disorder that is characterized by chronic abdominal discomfort or pain, bloating and changes in bowel habits. An IBS diagnosis is based on a pattern of symptoms that fit established criteria in conjunction with physical examination and tests that rule out other conditions with similar symptoms.
Health care professionals use a symptom checklist called the Rome Criteria to diagnose IBS. It requires that people have at least three months of recurrent abdominal pain or discomfort associated with two or more of the following:
Abdominal pain or discomfort that is:
relieved with defecation;
associated with a change in frequency of stool;
associated with a change in form (appearance) of stool.
Other symptoms include:
altered stool frequency (often defined in research studies as more than three bowel movements per day or fewer than three bowel movements per week);
altered stool form (lumpy/hard or loose/watery stool);
altered stool passage (straining, urgency or feeling of incomplete evacuation);
passage of mucus; and/or
bloating or feeling of abdominal distension.
While most people with IBS meet these criteria for symptoms, some don't. That doesn't mean they don't have IBS. Also, some people with other gastrointestinal illness may meet the Rome Criteria but not have IBS. So you can't diagnose yourself simply with a list of symptoms. You must work closely with your doctor, who should also take a complete medical history and conduct a full physical exam along with necessary tests to determine your diagnosis.
It's important to remember, however, that everyone suffers from an occasional bowel disturbance. A normal bowel movement is one that is formed but not hard, contains no blood and is passed without cramps or pain. Changes in bowel habits can occur with changes in diet or activity and don't necessarily indicate IBS. If you have IBS, such disturbances are chronic and recurrent.
IBS symptoms cause more than just physical distress. You may also suffer stress, depression, anxiety and frustration, at least in part because IBS can be embarrassing and not easy to talk about. A common source of anxiety relates to the need to be near a toilet when the feeling of urgency develops. Some people with moderate to severe symptoms (including unpredictable pain, urgency and perhaps even bowel incontinence) find that IBS can affect many aspects of their lives, from the most public (including the ability to work, attend social events and travel) to the most private (relationships with friends, family and sexual partners).
Moreover, IBS symptoms are an example of what researchers call the "mind-gut" connection. That is, having IBS often causes stress and stress often triggers more symptoms. That's because the colon is partly controlled by the nervous system. When areas of the brain that are influenced by stress are overwhelmed, the gastrointestinal tract is affected, causing pain and other symptoms. Then increased pain can cause further anxiety.
A psychological evaluation and possible treatment may be recommended, particularly when symptoms are severe enough to affect your quality of life. Questionnaires that detect anxiety, depression or other psychological problems may be used to supplement your health care provider's evaluation of your symptoms. Psychological treatment, in addition to medical treatment, can break the vicious IBS symptom cycle.
In addition to taking a complete medical history that includes a careful description of symptoms, your health care professional may do one or more of the following:
Order lab tests. (There is no lab test specifically for IBS, but thyroid, blood and urine tests may be able to eliminate other conditions that cause similar symptoms.)
Order a flexible sigmoidoscopy or, for older patients, a colonoscopy. These procedures involve viewing the colon through a flexible tube inserted through the anus. (For instance, during flexible sigmoidoscopy, the rectum, sigmoid colon and descending colon are directly viewed using a flexible tube with a light on the end. Colonoscopy is a similar procedure, which involves viewing the entire colon through a flexible tube inserted through the anus.) The point is to look for signs of other disease but the test may not be necessary in all patients.
Conduct a pelvic exam to rule out ovarian tumors and cysts or endometriosis, which may cause symptoms similar to IBS.
Test for lactose intolerance. Lactose is a sugar found in dairy products that causes gastrointestinal distress in some people. To test for this, your health care professional may ask you to eliminate milk products from your diet for two weeks; if your symptoms improve, you may be lactose intolerant and not have IBS. A lactose hydrogen breath test may also be used to indicate lactose intolerance.
Test a stool sample for evidence of bleeding. Your health care professional may take a sample during a rectal exam, or you may be asked to take a sample yourself. How you do this depends on the on the type of kit you receive. One kit supplies a special paper you use to collect the sample. You then return it to the lab in the container provided. Be sure to get complete instructions from your health care professional.
Order an imaging test of the bowel and abdomen, such as a CT scan or small bowel series.
Test for gluten allergy, called celiac disease.
Your treatment for irritable bowel syndrome (IBS) will depend on which symptoms you have. Your health care professional and you will work out a personal treatment plan. If you suffer from diarrhea, you won't need the same approach as someone who is constipated. And you might want to consider visiting a specialist. Talk to your health care professional about whether you need a referral to a gastroenterologist.
If your health care professional says the problem is "all in your head," or that there's nothing that can be done, get a second opinion. Many women with IBS manage their condition successfully. Look for a health care professional who explains IBS and is interested in helping you identify the triggers for your symptoms.
Your treatment plan may take into consideration physical triggers as well as psychological and environmental factors. It may include one or more of the following: lifestyle changes, pharmacological treatment and psychological treatment. Discovering an IBS management plan that works for you likely will involve trial and error at first and changes along the way.
Here are some of the areas your treatment plan may encompass:
Certain foods may trigger an attack. It is a good idea to keep a journal noting which foods seem to cause distress. To identify foods that trigger your symptoms, maintain your usual diet and note what you were eating when your symptoms developed. Look for patterns. Often, symptoms don't relate to specific foods, rather large amounts of food at one time. You may want to consult a dietitian to help you identify food triggers and develop your treatment plan. He or she may be able to help you assess how your body reacts to certain foods. Sometimes a food sensitivity (such as lactose intolerance) may be involved.
Triggers for some people can include caffeine, milk, chocolate, nicotine, alcohol and large, high-fat meals. Other people with IBS may tolerate these without symptoms.
Traditional therapies have included dietary fiber, especially for treating constipation. Fiber decreases the transit time through the colon and decreases the pressure in the colon. Increasing your consumption of fresh fruits and vegetables, whole grains and bran may help; your health care professional may also suggest a soluble fiber supplement.
Increased fiber can make symptoms worse for some IBS patients. This is because bacteria in the colon can break down fiber, producing gas, which can make bloating worse. Discuss fiber options with your health care professional. You may need to avoid certain forms of fiber, particularly gas-forming foods such as cabbage, broccoli, cauliflower and beans. But there's no conclusive proof that eliminating certain foods will eliminate your symptoms.
Your health care professional may suggest medications to manage your IBS symptoms.
Drug therapies suggested by your health care professional for IBS may include:
Antispasmodic anticholinergics These medications reduce intestinal spasms and can diminish the pain, bloating and discomfort associated with IBS. Two examples include dicyclomine (Bentyl) and hyoscyamine (Levsin). Studies show these drugs have limited effectiveness and are best used when symptoms develop soon after meals. Side effects may include dry mouth/nose/throat, rapid heartbeat, constipation, blurred vision and problems with urination.
Antidiarrheals such as loperamide (Imodium). These medications are quite effective for diarrhea and may be prescribed as needed to help with loose, frequent stools or urgency.
Bulk laxatives (such as fiber) may be in order if your primary symptom is constipation. These include psyllium (Metamucil), methylcellulose (Citrucel) and calcium polycarbophil (Equalactin).
Alosetron (Lotronex) is approved for use in female patients who have severe diarrhea and abdominal pain as symptoms of IBS. It is a 5HT 3 receptor antagonist and inhibits the action of serotonin in the gut. Lotronex was withdrawn from the market soon after it was introduced because of safety concerns, but it was subsequently reintroduced and is currently available. However, because of its potentially serious side effects, Lotronex should be used only in patients with severe symptoms who are cared for by a gastroenterologist, and certain prescribing guidelines must be followed.
Tricyclic antidepressants such as amitriptyline ( Vanatrip, Elavil, Endep ), desipramine (Norpramin) and nortriptyline (Pamelor, Aventyl) are often used for symptoms of pain and diarrhea. They are used in doses lower than the dose used for depression and are believed to work by decreasing the pain signals between the gut and brain. These medications may also help with sleep disturbances as well as fibromyalgia, which is commonly seen with IBS.
Selective serotonin reuptake inhibitors (SSRS) may also be prescribed to alleviate the accompanying depression and anxiety suffered by some IBS patients. These drugs include SSRIs such as fluoxetine (Prozac), sertraline (Zoloft) and paroxetine (Paxil). Other types of antidepressants may also be recommended, including mirtazapine (Remeron), venlafaxine (Effexor) and duloxetine (Cymbalta).
Anti-anxiety medications help reduce anxiety that can worsen IBS symptoms. Physicians occasionally prescribe anti-anxiety drugs such as diazepam (Valium), lorazepam (Ativan) and clonazepam (Klonopin) for people with short-term anxiety that is worsening their IBS. These drugs should only be taken with close follow-up by your doctor, however, because they can become addictive.
Lubiprostone (Amitiza) is a drug that increases intestinal fluid secretion. It is used to treat severe constipation and IBS in women over 18 who have not responded to other treatments.
Antibiotics may play a role in the treatment of IBS, but the exact role is unclear at this point. Some people whose IBS symptoms are caused by an overgrowth of bacteria in the intestines may benefit from antibiotics, but no antibiotic is currently approved for this use yet.
Tips for Avoiding or Managing Common IBS Triggers
With IBS, your bowel is sensitive to stimuli. Identifying what triggers your abnormal bowel function can help prevent or minimize your symptoms. Here are some tips that might help:
Eat at regular hours; chew food slowly and thoroughly; avoid large or high-fat meals or excess caffeine.
Get regular physical activity. It can help relieve the symptoms of anxiety and also promotes good bowel function.
Avoid delaying the urge to have a bowel movement.
Avoid straining during a bowel movement; try to relax and take your time.
Because your colon is more sensitive and reactive if you have IBS, ordinary events such as eating and distention from gas or having other material in the colon can trigger symptoms. The following strategies may help prevent attacks:
An eating schedule. Eating causes contractions of the colon. Normally, this response may cause an urge to have a bowel movement within 30 to 60 minutes after a meal. If you have IBS, this urge may come sooner and trigger cramps and diarrhea.
Smaller meals. The strength of the response is often related to the number of calories in a meal and especially the amount of fat. Also, large meals can cause cramping and diarrhea in people with IBS. Symptoms may be eased if you eat smaller meals more often or just eat smaller portions. But try to stay on a regular eating schedule either way.
Dietary changes. For some people, a low-fat, higher-fiber diet may help. Other people feel better with a high-protein, low-carbohydrate diet. Fat greatly stimulates colon contractions following a meal. Caffeine causes loose stools in many people and is more likely to affect those with IBS. The key is that the diet needs to be individualized for each person.
Dietary fiber may lessen constipation in many cases but does not lessen pain. Whole-grain breads and cereals, beans, fruits and vegetables are good sources of fiber. (Over-the-counter fiber supplements can also provide valuable fiber, but consult your health care professional before using them.)
Certain medicines (including antibiotics) may trigger IBS attacks in some people. Be sure to tell all your health care professionals about your condition and discuss other medication options that can avoid triggering IBS symptoms.
Physical, emotional and environmental stress may exacerbate or trigger symptoms. Stress-reduction/relaxation strategies can help relieve or prevent IBS symptoms. Cognitive/behavioral therapy, stress-management counseling, hypnosis and relaxation may reduce IBS symptoms.
These treatments also reduce anxiety and other psychological symptoms. You may want to keep a record of what events and activities trigger your symptoms. In the case of IBS symptoms that are linked to childhood abuse or trauma, discovering the connection helps many patients gain better control of the disease.
Irritable bowel syndrome (IBS) isn't a condition that can be "prevented." It's not a condition you can avoid. Rather, its symptoms, including chronic abdominal cramping, discomfort or pain, bloating and changes in bowel habits, can be managed, often minimized and sometimes eliminated by addressing their triggers.
People with IBS have colons that are more sensitive to and overreact to both dietary (even to normal gastrointestinal activity) and environmental stimuli, like stress.
Though health care professionals don't know why some individuals suffer from IBS, while others never develop it, IBS is a real functional disorder. Don't believe anyone who tells you that your symptoms are "all in your head."
Facts to Know
Irritable bowel syndrome (IBS) is often confused with other conditions. It has been called by many names—colitis, mucous colitis, spastic colon, spastic bowel and functional bowel disease. Most of these terms are inaccurate. Colitis, for instance, means inflammation of the large intestine (the colon), while IBS doesn't cause inflammation.
IBS symptoms affect up to 20 percent of the general population and a higher percentage of women. It is the most common disorder diagnosed by gastroenterologists, and is among the most common health disorders in general.
Women are twice as likely as men to suffer from IBS. Moreover, they seem to have more symptoms during their periods, suggesting that reproductive hormones play a role.
IBS is a chronic condition. Typical onset occurs in the late 20s. You might have it for years—even all your life. Fortunately, the symptoms may come and go.
IBS can be triggered by stress, and symptom flares are associated with major stressful life events in the majority of patients. Studies indicate that some psychological treatments, such as cognitive behavioral therapy, can alleviate abdominal pain and diarrhea associated with the syndrome.
Although there is no cure, IBS is treatable. Symptoms can often be managed with dietary or lifestyle changes; in more severe cases, medication may be needed. Surgery is never considered a treatment option.
There is no known single, specific cause for IBS.
IBS symptoms vary by individual. They can include lower abdominal pain, bloating, excess gas, increased mucus in the stools, diarrhea and/or constipation, tiredness (even low-grade depression) and an urgent need to have a bowel movement (sometimes without being able to).
Certain medicines and foods may trigger attacks.
Other conditions often accompany IBS, such as fibromyalgia, interstitial cystitis (a bladder condition), anxiety and depression.
Questions to Ask
Review the following Questions to Ask about irritable bowel syndrome so you're prepared to discuss this important health issue with your health care professional.
How much experience do you have treating irritable bowel syndrome (IBS)? Should I see a specialist?
What tests are used to diagnose IBS? Are these tests covered by my insurance?
Do I need to change my diet? How?
Could any of the medications I'm taking be contributing to my symptoms?
Is it possible that other conditions could be causing these symptoms? Will the tests we're conducting rule out other conditions?
Could certain foods be causing my symptoms? How do we find out?
Are there clinical trials being conducted for IBS? Where can I find out about them?
Can you give me information about IBS support groups in the area or online?
What strategies can I take prior to and during my period to prevent my IBS symptoms from getting worse?
Do you know of any experimental treatments or clinical trials I might qualify for?
How will irritable bowel syndrome (IBS) affect my life?
It depends on the severity of your condition and the effectiveness of your treatment. Often, the condition is simply uncomfortable and annoying. But in rare cases, it can be debilitating.
Will I always have IBS?
Again, it varies. Some people have reported that their symptoms disappeared after a time. Others have symptoms their whole lives.
Will IBS lead to colon or rectal cancer?
No. It may even reduce your risk, since folks with IBS are often more in tune with their bowel functions and may have already had normal diagnostic tests. (And you will be relieved to know that IBS isn't associated with inflammatory bowel diseases such as ulcerative colitis or Crohn's disease.)
I had an unexplained bout of diarrhea last night. Do I have IBS?
Probably not, if it's not a pattern. Most adults occasionally suffer from unexplained diarrhea or nervous stomach. If it happens rarely, it's probably not IBS.
My health care professional wants me to seek counseling for my IBS—is that reasonable?
Yes, certain psychological treatments have been effective in reducing abdominal pain and diarrhea in IBS patients. These approaches include cognitive behavioral therapy, stress-management counseling, hypnosis and relaxation.
Medications, particularly tricyclic antidepressants in low doses, may help with physical pain, because they can affect the way pain messages are received by the brain. In addition to this therapeutic effect on pain, these medications when taken at higher doses can have a role in restoring balance to brain chemicals associated with depression, anxiety and other mood disorders.
What triggers an attack?
Several factors may trigger an attack: eating too fast or too much, a particular food, your period, your overall diet, stress, depression or medication—it can vary.
I'm having some of the symptoms of IBS. There's blood in my stool and I think I'm anemic. Are those symptoms, too?
No. They could be symptoms of a more serious condition. Make an appointment with your health care professional today.
What is the connection between stress and IBS?
Your gastrointestinal system is highly sensitive to stress, and this can trigger or worsen IBS symptoms. In addition, IBS can create additional stress in your life. Sometimes, counseling or centrally acting drugs are part of the treatment. But IBS is not a psychological or psychiatric disorder. (If your health care professional dismisses your symptoms, get a second opinion.)
Many IBS sufferers go undiagnosed.
Although up to 20 percent of the population suffers from IBS, only about 15 percent of people with the condition seek medical help. Individuals who have significant bowel distress and pain should contact their health care professional to gain an accurate diagnosis and begin treatment to reduce its symptoms.
Identify food triggers using a journal.
For IBS sufferers, tracking the foods you eat and noting the times you experience distress will help uncover connections between eating and symptoms of IBS. The International Foundation for Functional Gastrointestinal Disorders publishes a "Personal Daily Diary" that individuals can use to record data. (To download the diary for free, go to www.iffgd.org/store/viewproduct/PDD). Sufferers also can take detailed notes on their own for two to four weeks that should include the types and amounts of foods eaten and the time of consumption. It's important to also record the time and description of distressing bowel events or related pain and discomfort. The National Institute of Diabetes and Digestive and Kidney Disease recommends consulting with a registered dietician who can help interpret the connection between food consumption and irritable bowel problems and help modify your diet to minimize adverse episodes.
Modify your diet.
IBS patients can make basic eating modifications on their own to decrease symptoms of IBS. The following food groups may be associated with a worsening of IBS symptoms: high-fat foods; milk products; chocolate; alcohol; caffeinated drinks, such as coffee, tea, colas and energy drinks; sorbitol sweetener (found in some chewing gum); and foods that produce gas, such as beans and certain vegetables. However, not all people with IBS need to eliminate these or any foods. Many sufferers of IBS also are lactose intolerant, a condition that results in bowel distress and pain similar to IBS. People with lactose intolerance can experience dramatic reductions in symptoms by eliminating most milk products from their diet. Boosting water intake and adding fiber to the diet also can help alleviate some symptoms for women with IBS who experience constipation.
IBS patients more likely to have unnecessary surgery.
Before going under the knife, people with IBS should make sure the surgeries recommended by their health care professionals are really necessary. A study published in the medical journal Gastroenterology found IBS sufferers are at higher risk than others to have their gallbladders and appendixes removed unnecessarily. Hysterectomies and back surgery also were found to be more commonly performed on IBS patients among the nearly 90,000 individuals who participated in the survey. Gallbladder removal was twice as common for people with IBS than others without the syndrome, the study revealed. However, researchers found similar rates for coronary artery and peptic ulcer surgeries for survey respondents with and without IBS. If you're considering surgery and are unsure about whether surgery is the right choice, you may want to pursue a second opinion.
Stress management therapies can help.
Since stress is considered one of the triggers of IBS symptoms, some stress management therapies—including hypnosis and cognitive behavioral therapy—can be helpful for some women living with this condition. Such therapies can reduce anxiety levels, encourage health promoting behavior, increase patient responsibility and involvement in the treatment and improve pain tolerance.
Since a landmark study showing the effectiveness of hypnotherapy in treating IBS was published in The Lancet in 1984, more studies have demonstrated the treatment's effectiveness. Make sure a therapist using hypnosis is qualified to treat medical conditions. A partial list of clinicians can be found at the following site: www.ibshypnosis.com/IBSclinicians.html.
Organizations and Support
American College of Gastroenterology
Address: P.O. Box 342260
Bethesda, MD 20827
International Foundation for Functional Gastrointestinal Disorders (IFFGD)
Address: P.O. Box 170864
Milwaukee, WI 53217
Email: [email protected]
National Institute of Diabetes, Digestive and Kidney Diseases (NIDDK)
Address: Building 31, Room 9A06
31 Center Drive, MSC 2560
Bethesda, MD 20892
Wound, Ostomy and Continence Nurses Society (WOCN)
Address: 15000 Commerce Parkway, Suite C
Mt. Laurel, NJ 08054
Hotline: 1-888-224-WOCN (1-888-224-9626)
Medline Plus: Irritable Bowel Syndrome
Address: Customer Service
8600 Rockville Pike
Bethesda, MD 20894
Email: [email protected]
National Digestive Diseases Information Clearinghouse (NDDIC): Irritable Bowel Syndrome: What You Need to Know
Address: National Digestive Diseases Information Clearninghouse
2 Information Way
Bethesda, MD 20892
Email: [email protected]