Menu   WellSpan Health

Health Library

Health Library

Irritable Bowel Syndrome (IBS)

Illustration of the anatomy of the digestive system, adult

What is irritable bowel syndrome (IBS)?

Irritable bowel syndrome (IBS) is an intestinal disorder that causes the following:

  • Crampy pain

  • Gassiness

  • Bloating

  • Changes in bowel habits

IBS has inaccurately been called by many names, including the following:

  • Colitis

  • Mucous colitis

  • Spastic colon

  • Spastic bowel

  • Functional bowel disease

IBS is a functional disorder because there is no sign of disease when the colon is examined. Because doctors have been unable to find an organic cause, IBS often has been thought to be caused by emotional conflict or stress. While stress may worsen IBS symptoms, research suggests that other factors also are important.

IBS often causes a great deal of discomfort and distress, but it is not believed to:

  • Cause permanent harm to the intestines.

  • Lead to intestinal bleeding of the bowel.

  • Lead to a serious disease such as cancer.

It has not been shown to lead to serious, organic diseases, nor has a link been established between IBS and inflammatory bowel diseases such as Crohn's disease or ulcerative colitis.

What causes irritable bowel syndrome?

The digestion and propulsion of nutrients and fluids through the gastrointestinal system (GI) is a very complicated and very well-organized process. The GI tract has its own intrinsic muscles and nerves that connect, like an electrical circuit, to the spinal cord and brain. Neuromuscular events occurring in the GI tract are relayed to the brain through neural connections, and the response of the brain is also relayed back to the gastrointestinal tract. As a result of this activity, motility and sensation in the bowel are generated. An abnormality in this process results in a disordered propulsion of the intestinal contents, which generates the sensation of pain.

The exact cause of IBS is unknown. One theory is a person with IBS may have a colon that is more sensitive and reactive than usual, so it responds strongly to stimuli that would not affect others. The colon muscle of a person with IBS then begins to spasm after only mild stimulation or ordinary events such as the following:

  • Eating

  • Distention from gas or other material in the colon

  • Certain medications

  • Certain foods

Women with IBS seem to have more symptoms during their menstrual periods, suggesting that reproductive hormones can increase IBS symptoms.

What are triggers for IBS?

The most likely triggers for IBS are diet and emotional stress. Scientists have some clues as to why this happens. Consider the following:

  • Diet. Eating causes contractions of the colon, normally causing an urge to have a bowel movement within 30 to 60 minutes after a meal. Fat in the diet can cause contractions of the colon following a meal. With IBS, however, the urge may come sooner, accompanied by cramps and diarrhea.

  • Stress. Stress stimulates colonic spasm in people with IBS. Although not completely understood, it is believed to be because the colon is partly controlled by the nervous system. Counseling and stress reduction techniques can help relieve the symptoms of IBS; however, this does not mean IBS is the result of a personality disorder. It is at least partly a disorder of colon motility.

What are the symptoms of IBS?

The following are the most common symptoms of IBS. However, each individual may experience symptoms differently. Symptoms may include:

  • Crampy abdominal pain

  • Constipation and diarrhea

  • Mucus may be in the bowel movement

Bleeding, fever, weight loss, and persistent, severe pain are not symptoms of IBS, but indicate other problems. The symptoms of IBS may resemble other medical conditions or problems. Always consult your doctor for a diagnosis.

How is irritable bowel syndrome diagnosed?

Your doctor will obtain a thorough medical history, perform a physical examination, and obtain screening laboratory tests to assess for infection and inflammation. More than likely, all the screening tests and physical examination will be normal. In most cases  IBS  is a diagnosis of exclusion. The laboratory tests, imaging studies, and procedures to be performed will be dictated by the history and physical examination. Tests and procedures that your doctor may order may include the following:

  • Blood tests. These are done to determine if you are anemic, have an infection, or have an illness caused by inflammation or irritation.

  • Urine analysis and culture. These are done to help diagnose urinary tract infections.

  • Stool culture. This checks for the presence of abnormal bacteria in the digestive tract that may cause diarrhea and other problems. A small sample of stool is collected and sent to a laboratory by your doctor's office. In two or three days, the test will show whether abnormal bacteria are present.

  • Fecal occult blood test. This checks for hidden (occult) blood in the stool. It involves placing a very small amount of stool on a special card, which is then tested in the doctor's office or sent to a laboratory. If blood is present, it may suggest an inflammatory source in the gastrointestinal tract.

  • Esophagogastroduodenoscopy (also called EGD or upper endoscopy). A procedure that allows the doctor to examine the inside of the esophagus, stomach, and duodenum (the first part of the small intestine where absorption of vitamins, minerals, and other nutrients begins). A thin, flexible, lighted tube, called an endoscope, is guided into the mouth and throat, then into the esophagus, stomach, and duodenum. The endoscope allows the doctor to view the inside of this area of the body, as well as to insert instruments through the scope for the removal of a sample of tissue for biopsy (if necessary).

  • Abdominal X-rays. A diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs on film.

  • Abdominal ultrasound. A diagnostic imaging technique which uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels. Gel is applied to the area of the body being studied, such as the abdomen, and a wand called a transducer is placed on the skin. The transducer sends sound waves into the body that bounce off organs and return to the ultrasound machine, producing an image on the monitor. A picture or video recording of the test is also made so it can be reviewed in the future.

  • Colonoscopy. A procedure that allows the doctor to view the entire length of the large intestine, and can often help identify abnormal growths, inflamed tissue, ulcers, and bleeding. It involves inserting a colonoscope, a long, flexible, lighted tube, in through the rectum up into the colon. The colonoscope allows the doctor to see the lining of the colon, remove tissue for further examination, and possibly treat some problems that are discovered.

What is the treatment for IBS?

Specific treatment for IBS will be determined by your doctor based on:

  • Your age, overall health, and medical history

  • Extent of the condition

  • Your tolerance for specific medications, procedures, or therapies

  • Expectations for the course of the condition

  • Your opinion or preference

Treatment may include:

  • Changes in diet. Eating a proper diet is important with irritable bowel syndrome. In some cases of IBS, a high-fiber diet can reduce the symptoms. Keeping a list of foods that cause distress, and discussing the findings with a doctor or registered dietitian, can help. Fiber supplements may also be used.

  • Medication. There are both prescription and non-prescription medicines for IBS including:

    • Medications for constipation 

    • Medications for diarrhea

    • Tricyclic antidepressants

    • Antispasmodic medicines

What are good fiber sources?


Moderate fiber

High fiber


Whole wheat bread, granola bread, wheat bran muffins, Nutri-Grain waffles, popcorn



Bran Flakes, Raisin Bran, Shredded Wheat, Frosted Mini Wheats, oatmeal, Mueslix, granola, oat bran

All-Bran, Bran Buds, Corn Bran, Fiber One, 100% Bran


Beets, broccoli, brussels sprouts, cabbage, carrots, corn, green beans, green peas, acorn and butternut squash, spinach, potato with skin, avocado



Apples with peel, dates, papayas, mangos, nectarines, oranges, pears, kiwis, strawberries, applesauce, raspberries, blackberries, raisins

Cooked prunes, dried figs

Meat substitutes

Peanut butter, nuts

Baked beans, black-eyed peas, garbanzo beans, lima beans, pinto beans, kidney beans, chili with beans, trail mix

Irritable Bowel Syndrome (IBS) - WellSpan Health

Online Medical Reviewer: Berry, Judith, PhD, APRN
Online Medical Reviewer: Holloway, Beth, RN, M.Ed.
Online Medical Reviewer: Weisbart, Ed, M.D.
Last Review Date: 2012-04-17T00:00:00
Last Modified Date: 2015-02-06T00:00:00
Posting Date: 2008-11-30T00:00:00
Published Date: 2015-02-06T00:00:00
Last Review Date: 2007-03-30T00:00:00
© 2015 WellSpan Health. All Rights Reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

I would like to:

Are you sure you would like to cancel?

All information will be lost.

Yes No ×

About the provider search

This search will provide you with WellSpan Medical Group and Northern Lancaster County (Ephrata) Medical Group primary care physicians and specialists. If we don’t have a WellSpan Medical Group physician to meet your criteria, the search will expand to include community physicians who partner with WellSpan Medical Group physicians through the WellSpan Provider Network or provide care to patients on the Medical Staffs of WellSpan’s Hospitals.


Schedule Your Next Appointment Online with MyWellSpan

Use your MyWellSpan patient portal any time to view available appointments, and pick the date and time that best suits your schedule.

Go to MyWellSpan

New to this practice?

If you don't have a WellSpan primary care provider and would like to schedule a new patient appointment with a provider who is accepting patients, just log into your MyWellSpan account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to see the offices that are accepting new patients in relation to your zip code. If you are not enrolled in MyWellSpan, go to, call 1-866-638-1842 or speak with a member of the staff at a participating facility to sign up. New patient scheduling not available at all practices/programs.

Already a patient at this practice?

If you already have a relationship with a WellSpan practice, simply log into your account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to schedule an appointment with any provider or practice that already counts you as a patient. Online scheduling varies by practice/program.