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Irritable bowel syndrome
Other Resources UpToDate PubMed

Irritable bowel syndrome

Contributors: Michael W. Winter MD, Nishant H. Patel MD, Desiree Rivera-Nieves MD, Khaled Bittar MD
Other Resources UpToDate PubMed


Irritable bowel syndrome (IBS) is a functional bowel disorder characterized by abdominal pain and altered bowel habits, either constipation or diarrhea, in the absence of any identifiable abnormality in the gastrointestinal tract. It accounts for approximately 25%-50% of outpatient gastroenterology referrals, and it is the second highest cause of work absenteeism in the United States. IBS has a female predominance.

IBS is a diagnosis of exclusion, as it has no histologic phenotype and no sensitive or specific laboratory tests. However, recent American College of Gastroenterology guidelines recommend a diagnostic testing strategy to expedite the time of diagnosis, decreasing delays in treatment (see References section).

Rome III diagnostic criteria require recurrent abdominal pain at least 1 day per week over 3 months, associated with 2 of the following:
  • Pain related to defecation
  • Change in frequency of stool (constipation or diarrhea)
  • Change in appearance of stool
Manning diagnostic criteria require at least 2 of the following:
  • Onset of pain linked to more frequent bowel movements
  • Looser stools associated with the onset of pain
  • Pain relieved by passage of stool
  • Noticeable abdominal bloating
  • Sensation of incomplete evacuation more than 25% of the time
  • Diarrhea with mucus more than 25% of the time
Four subtypes of IBS are recognized:
  • IBS with constipation – Hard / lumpy stools > 25% and loose / watery stools < 25%
  • IBS with diarrhea – Loose / watery stools > 25% and hard / lumpy stools < 5%
  • Mixed IBS – Hard / lumpy stools > 25% and loose / watery stools > 25%
  • Un-subtyped IBS – No consistent pattern of stool abnormality
Onset of IBS can occur at any age and is not curable. It does not progress, and patients can often find symptom relief through a variety of treatment options.


K58.9 – Irritable bowel syndrome without diarrhea

10743008 – Irritable Bowel Syndrome

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Last Reviewed:10/31/2017
Last Updated:02/04/2021
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Patient Information for Irritable bowel syndrome
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Contributors: Medical staff writer


Irritable bowel syndrome (IBS) is characterized by abdominal discomfort and changes in bowel habits. Irritable bowel syndrome can cause either constipation or diarrhea and often leads to cramping, bloating, gas, and abdominal pain.

Who’s At Risk

Some risk factors for IBS are:
  • Age younger than 45
  • Women are twice as likely to get IBS
  • Family history of IBS
  • Mental health problems such as depression, personality disorder, and other stress-related disorders
  • Recent gastrointestinal infection (virus, Salmonella, etc.)

Signs & Symptoms

The symptoms of IBS are:
  • Abdominal pain or discomfort
  • Bloating or gas
  • Mucus in stool
  • Diarrhea or constipation, sometimes alternating

Some factors can make IBS symptoms more severe:
  • Certain foods cause more severe symptoms.
  • Stress can make symptoms worse.
  • Hormones play a role in IBS with many women claiming their symptoms of IBS intensify around their menstrual periods.

Self-Care Guidelines

The following guidelines should be followed when you have irritable bowel syndrome:
  • Slowly increase the amount of fiber ingested.
  • Avoid foods that make your symptoms worse such as alcohol, chocolate, coffee, dairy products, spices, fatty foods, gluten, and sugar sweeteners.
  • Reduce consumption of gas-causing foods, such as carbonated soft drinks and raw fruits and vegetables (broccoli, cabbage, cauliflower).
  • Drink plenty of fluids.
  • Eat at regular times during the day. Some people find that eating small meals throughout the day is better than 3 large meals.
  • Introduce relaxation activities into your daily routine to reduce stress.
  • Join a local or online support group for people with IBS to help develop coping skills and to minimize disruption in your life caused by IBS.

When to Seek Medical Care

If symptoms of IBS become severe or do not resolve on their own, contact your health care provider. If you have rectal bleeding, weight loss, or abdominal pain that is getting worse or occurs at night, contact your health care provider.


Treatment focuses on relieving the symptoms of IBS. By following the self-care guidelines above and managing your stress, you can help reduce symptoms.

Your primary care physician may refer you to counseling or suggest other methods to help you reduce stress, such as relaxation exercises, mindfulness training, deep breathing techniques, cognitive behavioral therapy, and biofeedback.

If symptoms cannot be managed with the self-care guidelines, medication is available. Anticholinergic and antispasmodic medicine can help reduce pain during bowel spasms. Antibiotics can be used to control bacterial overgrowth in the intestines. Other medications may be prescribed to relax the colon or increase fluid in the small intestine.
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Irritable bowel syndrome
A medical illustration showing key findings of Irritable bowel syndrome : Abdominal pain, Diarrhea, Abdominal cramp, Abdominal distension, Anxiety, Constipation, Indigestion, Recurring episodes
Copyright © 2023 VisualDx®. All rights reserved.