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Irritable bowel syndrome: Overview

Created: ; Last Update: October 20, 2016; Next update: 2019.


The typical symptoms of irritable bowel syndrome (IBS) include abdominal pain, constipation and diarrhea. Although IBS is not dangerous, the symptoms can be very painful and bothersome. Most people who have IBS have a mild form which they can cope with quite well without getting any treatment. But some people have symptoms that are so severe they significantly affect their everyday lives and cause distress. There is no cure for IBS. But over time, many people find out what helps and what makes things worse. And there are a number of different ways to relieve the symptoms.


The typical symptoms of IBS include persistent upper or lower abdominal pain, cramps, and changes in the consistency of stool. It tends to cause constipation in women and diarrhea in men, although some people may have both. Other signs of IBS may include feeling very full, flatulence (gas) or mucous discharge. The condition often comes and goes in episodes: Symptom-free periods are followed by periods of more severe symptoms.


IBS mostly affects the large intestine. The muscles of the large intestine move the food mass, which is still quite soft at first, slowly but steadily forward through the digestive tract. Water is taken out of it and the indigestible parts of the food form more solid stool.

If the muscles move the food mass through the intestine too quickly, too much water remains in the stool, causing diarrhea. If this process takes too long, on the other hand, people get constipation. Painful cramps may occur if the intestinal muscles contract violently.

Although the causes of IBS are not fully understood, there are many theories. For example, oversensitive nerves in the intestine, intestinal muscle disorders and inflammations of the intestinal wall are believed to all play a role. It has also been observed that IBS is more common in people who have had an intestinal infection with fever and severe diarrhea. IBS may be inherited as well. Psychological stress, eating habits and food intolerances are thought to be possible triggers too. Yet with many of these factors it isn’t clear whether they are a cause or result of IBS – or how much they actually contribute to the symptoms.


IBS mostly affects people between the ages of 35 and 50. Including the milder forms, about 14 out of 100 women and 9 out of 100 men have it.


There are several different medical criteria for diagnosing IBS. According to specialist medical associations in Germany, someone is considered to have irritable bowel syndrome if

  • symptoms such as abdominal pain or bloating last for more than three months and are usually connected with changes in bowel movements, such as more or less frequent bowel movements, diarrhea or constipation,
  • the symptoms have a noticeable impact on your quality of life, and
  • there is no reason to believe that the symptoms are being caused by another disease.

These kinds of symptoms may have other causes, though, such as lactose intolerance or gluten intolerance (celiac disease). Gluten is a protein that is found in different types of grains, and is an ingredient in many foods. Blood tests and other tests can be used to find out whether the symptoms are being caused by either of these food intolerances. But some people have both irritable bowel syndrome and a food intolerance at the same time.

If you have any of the following symptoms as well, they are likely to be caused by another bowel problem:

  • Significant weight loss
  • Blood in the stool
  • Fever
  • Anemia

These could be signs of something else, like an inflammatory bowel disease such as ulcerative colitis or Crohn’s disease. Another possible cause is diverticulitis – an inflammation caused by stool getting stuck in pockets in the bowel wall. Sudden and severe abdominal pain could also be a sign of gallstones.

If digestive problems are accompanied by signs such as blood in the stool, bowel cancer may be a possible cause. But it is very rare in people under the age of 50.


There are a lot of different opinions about what can help relieve irritable bowel syndrome. Common recommendations include eating or avoiding certain foods and getting exercise. But most of this advice has not been tested in good-quality studies. If you ask different people who have IBS, it becomes clear that something that helps one person may end up making someone else’s symptoms worse. So it is best to try out different things and see for yourself if it helps.

For example, someone who thinks that a particular type of food is making their symptoms worse can try to avoid eating it for a while. Some people have fewer symptoms if they eat their meals in smaller portions throughout the day. Keeping a diary can help you figure out whether doing specific things like exercising more or avoiding certain types of food have any effect. You can make a note of what you eat, how physically active you are, and how stressed you are over a longer period of time. It might be possible to recognize patterns after a while.

There are also a number of different treatments that aim to relieve the symptoms. Because the causes of IBS are not clear, it is difficult to find suitable treatments. But research has suggested that at least some medications and treatments may help. Treatments for IBS include:

  • Fiber supplements, for instance made from psyllium
  • Peppermint oil
  • Probiotics
  • Anti-cramping medications
  • Medications for constipation or diarrhea
  • Various medications, such as antibiotics or antidepressants
  • Psychological treatments, such as stress management or hypnosis

Because medications in particular can have a number of side effects and sometimes even make the symptoms worse, it is worth carefully considering the potential advantages and disadvantages of taking them.

Everyday life

Most people who have a milder form of IBS cope quite well with it. Yet for some the symptoms are so strong that it has a big impact on their quality of life. Some people are never really sure when they will need to go to the toilet, and they feel that they have lost control over their body. This can make everyday life very difficult because meals and appointments have to be carefully coordinated to get the timing right. This makes it nearly impossible to be spontaneous.

People often feel ashamed too. No one enjoys talking about intestinal problems, and many are embarrassed about needing to go to the toilet so often or passing a lot of wind. What’s more, IBS isn’t always taken seriously by other people – including doctors – perhaps because it isn’t a serious disease or because they consider it to be merely “in your head.” This can be very hurtful for those affected.

But most people find ways to live with IBS without it affecting their lives too much. It is sometimes the little things that make day-to-day life easier and help you to stop worrying all the time. For instance, bringing along your own food to a party, finding out right away where the bathroom is, or taking an aisle seat at the movies.


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  • IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

    Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. We do not offer individual consultations.

    Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Bookshelf ID: NBK279416


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