Irritable Bowel Syndrome

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What is irritable bowel syndrome?

Irritable bowel syndrome (IBS) is a gastrointestinal disorder that produces abdominal pain, bloating, cramping, constipation, and diarrhea. Two forms of IBS are common, one that is accompanied by bloating, constipation, and abdominal fullness, and another in which diarrhea is present. Although IBS is not life threatening, its symptoms can severely erode quality of life and may even be disabling.

IBS is one of the most common syndromes in the United States, affecting up to 20% of the population. It is more common in women than in men, and it usually begins before the age of 35. No specific anatomic abnormalities have been linked to IBS or any specific cause. There is no cure for IBS, but its symptoms are managed by medication, diet, and lifestyle changes. Unfortunately, up to 70% of patients with IBS do not get the proper treatment they need (Source: NDDIC).

People with IBS often report that stress management and activities, such as yoga and meditation, can have a calming and positive effect on their condition. Medications that may be prescribed for IBS include antidepressants, antidiarrheals, antispasmodics to control spasms in the colon, and fiber supplements. Dietary modifications, such as limiting dairy and gluten intake, can be helpful for some people.

Irritable bowel syndrome itself is not an emergency situation, but persistent diarrhea, a common symptom of the condition, can result in serious dehydration. Seek immediate medical care (call 911) for serious symptoms, such as severe abdominal pain, inability to pass gas or stool, vomiting blood, or blood in your stool.

Seek prompt medical care if you are being treated for irritable bowel syndrome but mild symptoms recur or persist.

What are the symptoms of irritable bowel syndrome?

Symptoms of irritable bowel syndrome (IBS) primarily affect the gastrointestinal system and include abdominal pain, discomfort, bloating, and fullness. IBS can occur with constipation and bloating as the main symptoms or with diarrhea, watery stools, and urgency.

Common symptoms of IBS with constipation

The form of IBS that is characterized by constipation may include the following symptoms:

Common symptoms of IBS with diarrhea

The form of IBS that is characterized by diarrhea may include the following symptoms:

  • Abdominal pain or cramping
  • Diarrhea
  • Loose, watery stools
  • Urgent need to pass stool

Serious symptoms that might indicate a life-threatening condition

In some cases, irritable bowel syndrome associated with persistent diarrhea can cause severe and sometimes life-threatening dehydration. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms including:

  • Bloody stool (blood may be red, black, or tarry in texture)
  • Inability to pass stool or gas
  • Severe abdominal pain
  • Vomiting blood

What causes irritable bowel syndrome?

The exact cause of irritable bowel syndrome (IBS) has not been determined, although there are several theories. One theory is that IBS may be an immune disorder, or one in which the intestines of the affected person are highly sensitive in responding to stress and bacteria. Certain foods are thought to trigger IBS flare-ups, including dairy products and gluten, which is present in wheat, barley and rye.

The epithelial layer, or lining, of the large intestine controls the amount of fluid in the bowel. In IBS, there appears to be a disruption in the function of fluid absorption. This can result in excessive fluid in the colon, which causes diarrhea and watery stools. Or, if the lining of the colon absorbs too much fluid from the colon contents, the stool may become dry, leading to constipation.

Bacteria in the intestinal tract have been found to have a connection to IBS. Some people develop IBS following bacterial gastroenteritis, an inflammation of the gastrointestinal (GI) tract caused by a bacterial infection.

Another theory of IBS points to a potential role of serotonin, a chemical that transmits nerve signals from one part of the body to another. Excessive levels of serotonin may result in diminished bowel movement and motility function, producing the symptoms of IBS.

What are the risk factors for irritable bowel syndrome?

A number of factors increase the risk of developing irritable bowel syndrome (IBS). Not all people with risk factors will get IBS. Risk factors for IBS include:

  • Depression
  • Feelings of stress
  • Female gender
  • History of adult sexual or domestic abuse
  • History of childhood sexual abuse
  • Ingestion of certain foods, such as dairy products or gluten
  • Previous gastrointestinal infections such as gastroenteritis

How is irritable bowel syndrome treated?

Currently, there is no cure for irritable bowel syndrome (IBS). The goal of treatment is to ease the symptoms, remedy the nutritional deficiencies, and reduce the number of recurrences, or flare-ups.

Medications for IBS

Depending on the form of IBS, the following types of medications may be used to treat its symptoms:

  • Alosetron (Lotronex) to manage the symptoms of IBS, such as diarrhea, pain and cramping
  • Antidepressants
  • Antispasmodics
  • Fiber supplementation and laxatives, such as psyllium (Fiberall, Metamucil) or methylcellulose (Citrucel)
  • Intestinal muscle relaxants

Dietary modifications for IBS

Symptoms of IBS may be reduced by dietary modifications including:

  • Avoiding foods that trigger flare-ups, such as dairy products, gluten, alcohol, or caffeine
  • Drinking plenty of liquids, especially water
  • Eating a high-fiber diet

What you can do to improve your IBS

In addition to following your health care provider’s treatment plan, you can take self-care measures to improve your IBS including:

  • Joining a support group to help cope with your symptoms
  • Modifying your diet
  • Practicing stress modification techniques, such as yoga or meditation

Complementary treatments

Some complementary treatments may help some people in their efforts to deal with IBS. These treatments, sometimes referred to as alternative therapies, are used in conjunction with traditional medical treatments. Complementary treatments are not meant to substitute for traditional medical care. Be sure to notify your doctor if you are consuming nutritional supplements or homeopathic (nonprescription) remedies as they may interact with the prescribed medical therapy.

Complementary treatments may include:

  • Acupuncture
  • Massage therapy
  • Nutritional dietary supplements, herbal remedies, tea beverages, and similar products
  • Yoga

What are the potential complications of irritable bowel syndrome?

Complications of untreated or poorly controlled irritable bowel syndrome (IBS) can be serious. You can help minimize your risk of serious complications by following the treatment plan that you and your health care professional design specifically for you. Complications of IBS include:

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Nov 13
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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