What Is Irritable Bowel Syndrome (IBS)?
Irritable bowel syndrome (IBS) is a disorder characterized most commonly by cramping, abdominal pain, bloating, constipation and diarrhea.
IBS causes a great deal of discomfort and distress, but it does not damage the intestines and does not increase the risk of cancer. Symptoms, however, can be uncomfortable and disruptive.
Roughly 10-15% of the U.S. population has IBS, according to the American Medical Association. It occurs more often in women than in men, and symptoms typically begin before the age of 35.
Most people can control their symptoms with diet, stress management and prescribed medications. For some people, however, IBS may require more extensive treatment.
Types of IBS
IBS is grouped by the pattern of bowel changes. Knowing your type of IBS helps guide treatment.
- IBS-C (constipation-predominant): Characterized by hard or infrequent stools
- IBS-D (diarrhea-predominant): Characterized by loose or urgent stools
- IBS-M (mixed type): Characterized by alternating constipation and diarrhea
Causes
The exact cause of IBS is not known. Contributing factors may include:
- Changes in gut motility (movement)
- Heightened pain sensitivity in the intestines
- Altered gut bacteria
- Prior gastrointestinal infection (post-infectious IBS)
- Stress and emotional factors
Certain triggers may worsen symptoms:
- Caffeine
- Large meals
- Stress
- Wheat, dairy or other specific foods
Women may notice symptoms worsen during menstrual cycles.
Signs & Symptoms
Abdominal pain, bloating and discomfort are the main symptoms of irritable bowel syndrome. However, symptoms can vary from person to person. Some people experience constipation. Often these people report straining and cramping when trying to have a bowel movement. They are frequently unable to produce any stool, or they are able to produce only a small amount. If they are able to have a bowel movement, there may be mucus in it, which is a fluid that moistens and protects passages in the digestive system.
Some people with IBS experience diarrhea. People with diarrhea frequently feel an urgent and uncontrollable need to have a bowel movement. Other people with IBS alternate between constipation and diarrhea. Sometimes people find that their symptoms subside for a few months and then return, while others report a constant worsening of symptoms over time.
Common IBS symptoms
- Abdominal pain or cramping
- Bloating
- Change in stool frequency
- Change in stool appearance
- Mucus in the stool
- Urgency with bowel movements
Pain is often relieved after a bowel movement. Some people have symptoms that come and go. Others experience more constant discomfort.
Red Flag Symptoms
The following symptoms are not typical of IBS and require medical evaluation:
- Anemia
- Fever
- Rectal bleeding
- Unexplained weight loss
- Persistent severe pain not related to bowel movements
Again, these are not common IBS symptoms and may indicate other problems such as inflammation, or rarely, cancer.
Diagnosis
IBS is generally diagnosed on the basis of a complete medical history that includes a careful description of symptoms and a physical examination.
Although there is no specific test for IBS, diagnostic tests may be performed to rule out other problems.
Lab Tests
Blood Tests
Blood tests cannot confirm IBS, but they can help rule out other conditions that cause similar symptoms. Doctors may order blood work to check for anemia, inflammation or signs of celiac disease. If test results are normal and symptoms meet IBS criteria, this supports the diagnosis.
Procedures
Colonoscopy
A colonoscopy allows the doctor to look inside the colon. This is done by inserting a small, flexible tube with a camera on the end of it through the anus. The camera then transfers the images of your colon onto a large screen for the doctor to see.
Endoscopy
An endoscopy is a procedure in which a doctor uses a thin, flexible tube with a camera to look inside the digestive tract. It allows direct visualization of the esophagus, stomach or intestines to check for abnormalities. Doctors may use an upper endoscopy to rule out other conditions, such as celiac disease, that can cause symptoms similar to IBS.
Sigmoidoscopy
A sigmoidoscopy allows the doctor to look inside the rectum and sigmoid colon using a small flexible tube. The sigmoid colon is the last 1-2 feet of the colon (large intestine) near the rectum. Your doctor may also do a biopsy and remove any polyps (small growths) found inside your rectum or sigmoid colon during the sigmoidoscopy. A biopsy is a small amount of tissue taken from the lining of the colon which can be studied closely to help determine your diagnosis and the best treatment for you.
If your test results are negative, the doctor may diagnose IBS based on your symptoms, including how often you have had abdominal pain or discomfort during the past year, when the pain starts and stops in relation to bowel function, and how your bowel frequency and stool consistency have changed.
Treatment
Unfortunately, many people suffer from irritable bowel syndrome for a long time before seeking medical treatment.
Up to 70% of people suffering from IBS are not receiving medical care for their symptoms, according to research published in the World Journal of Gastroenterology. No cure has been found for IBS, but many options are available to treat the symptoms. Your doctor will give you the best treatments for your symptoms and encourage you to manage stress and make changes to your diet.
Medications
Medication depends on IBS type and symptom severity.
Options may include:
- Antidiarrheal medications for IBS-D
- Antispasmodics for abdominal cramping
- Certain antidepressants to reduce pain sensitivity
- Laxatives or prescription medications for IBS-C
Treatment plans are individualized.
Lifestyle Management
Lifestyle changes can play an important role in managing IBS symptoms. Many people find that daily habits such as diet, stress management and physical activity affect how their digestive system functions.
Helpful strategies include:
- Eating regular, balanced meals and avoiding large or heavy meals that may trigger symptoms
- Keeping a food and symptom diary to identify personal triggers
- Managing stress through relaxation techniques, mindfulness or counseling
- Staying physically active, which can support normal bowel function
- Staying well hydrated, especially if diarrhea is present
Clinical Trials
Clinical trials help determine new treatment options for diseases and conditions. Patients with IBS have access to clinical trials and should speak with their physician to determine what trials might work best for them.
Programs and Services
Clinical Trials