Irritable Bowel Syndrome (IBS) and Functional Bowel Disorders

The University of Michigan Functional Bowel Disorders Clinic is dedicated to the comprehensive and multidisciplinary diagnosis and treatment of patients with functional bowel disorders and Irritable Bowel Syndrome. Functional bowel disorders is a term that describes a problem with how the stomach and bowels function or work. Irritable bowel syndrome and functional dyspepsia are two types of functional bowel disorders. Physically, all the organs are normal, but there are still signs that something is wrong. 
Irritable bowel syndrome (IBS) describes a group of symptoms that include lower stomach pain that may go away after having a bowel movement. Symptoms also include bloating, constipation and/or diarrhea. It is estimated that about 20% of Americans have irritable bowel syndrome. Irritable bowel syndrome cannot be diagnosed from an x-ray or a blood test. It is based on the symptoms the person reports to their doctor after other causes are ruled out. 
Functional dyspepsia (FD) is a condition that can include pain above your belly button, bloating, and nausea (often without vomiting). This disorder has also been called “nonulcer dyspepsia” or “nervous stomach.” A feeling of fullness in the stomach can prevent people with functional dyspepsia from eating a normal meal. Pain and/or bloating for many hours after eating are also common symptoms. Unlike irritable bowel syndrome, the pain does not get better after going to the bathroom.          

Functional Bowel Disorders and Irritable Bowel Syndrome Symptoms

Symptoms of functional bowel disorders include:

Functional bowel disorders are very common. Millions of people have some type of functional bowel disorder.

Comprehensive Diagnosis for Functional Bowel Disorders

In the Functional Bowel Disorders Clinic, our multidisciplinary team is committed to making the right diagnosis, and ruling out any other conditions, such as an inflammatory bowel disease like Crohn’s disease or ulcerative colitis. To diagnose, we perform a comprehensive examination and collect a thorough history. Rome III criteria, a set of criteria developed by experts on digestive diseases (including experts from the University of Michigan) to help determine functional bowel disorders, is also used to assess your symptoms.

To meet Rome III criteria for irritable bowel syndrome:
  • Your symptoms must have begun at least 6 months ago
  • You have stomach pain or discomfort for at least 3 days a month for the last 3 months
  • At least two of the following statements are true: Pain is relieved by having a bowel movement; pain is linked to a change in how often you have a bowel movement; pain is linked to a change in the appearance of your stool.

 To meet Rome III criteria for functional dyspepsia:

  • Your symptoms must have begun at least 6 months ago
  • You have one or more of the following symptoms: Bothersome fullness after eating a meal; you become full quickly while eating; pain in upper central portion of the abdomen; burning in upper central portion of the abdomen;
  • And there is no evidence of structural disease that is likely to explain the symptoms.

Your doctor may order tests through our comprehensive gastrointestinal lab to rule out other conditions, which can include:

  • Colonoscopy and flexible sigmoidoscopy: Used for initial diagnosis, both use a thin, flexible fiberoptic scope with camera to examine different areas, including the colon, small intestine and large intestine to see any ulcers, bleeding and inflammation.
  • Upper endoscopy: Uses a thin, flexible fiberoptic scope with camera inserted through the mouth, following the tract to the stomach and upper small intestine to look for bleeding, ulcers and inflammation.
  • Esophageal manometry: Uses a thin, flexible tube to measure the muscles of the esophagus and the function of the lower esophageal sphincter to see how well you are swallowing and digesting food.
  • Anorectal manometry: A thin, flexible tube with a balloon at the end is inserted into the rectum to measure the tone in the anal sphincter and rectal muscles to determine problems with moving the bowels.
  • Laboratory tests: Blood work plus stool samples to check for bacteria and intestinal bleeding.
  • Imaging tests: Collaborating with experts in Radiology for imaging and interpreting gastrointestinal abnormalities, including abdominal x-rays, barium enema, computed tomography (CT scan), magnetic resonance imaging (MRI) and assessment of stomach emptying.

Treatment Options for Irritable Bowel Syndrome and Functional Dyspepsia

There are no cures for functional bowel disorders. Patients suffering from these gastrointestinal disorders will all experience abdominal pain and discomfort, but then have varying degrees of constipation, diarrhea, bloating and urgency. To treat effectively, it’s important for our team—which includes gastrointestinal physicians, a board-certified dietician, physical therapists, and a behavioral therapist—to understand your frequency and severity of symptoms, from being a nuisance to mapping out every bathroom from home to the workplace to avoid an accident, so we can create an individualized plan that’s right for you.

Diet plus lifestyle changes, such as decreasing stress and adding an exercise program, are often all that’s needed for those whose symptoms are mainly a nuisance. Our team, which includes a board-certified dietitian, will create a treatment plan individualized for your needs. Learn more about how we are exploring the links between food and health by visiting our Culinary Medicine and Culinary Medicine Classes pages, where you can also learn about classes designed to demonstrate recipes related to specific medical conditions.
Over-the-counter or prescription medication is an option when diet and lifestyle changes aren’t enough. A variety of medications are available, and your doctor will determine which medicine(s) is right for you based on your symptoms and needs.
Physical therapy and/or biofeedback training (an alternative therapy that uses the mind to control a body function using guidance from a biofeedback instructor) can be used to help retrain the muscles of the pelvic floor and/or anal sphincter. 

Clinical trials are an option for those who qualify. We are a key site for the development of virtually every drug to treat IBS in the last 10 years.

Clinical Research Studies at the Functional Bowel Disorders Clinic

There are several ongoing clinical studies related to functional bowel disorders at the University of Michigan. These studies are designed to improve our ability to diagnose and treat these disorders. If you are interested in learning more or participating in a study, talk with your health care provider, or go to, the University of Michigan's website about clinical studies for health research, and follow these steps to find FBD clinical studies:
  • Click on the Volunteers heading
  • In the drop-down menu, click on Find Studies
  • On the next page, click on Search by Condition
  • The next page will be a list of conditions—scroll down to Stomach/Esophagus/Bowel Conditions

Other Information About Digestive and Liver Health

To see related gastroenterological services we offer, visit our Digestive and Liver Health overview page.

Make an Appointment

To schedule an appointment to discuss your need for treatment for Irritable Bowel Syndrome or another functional bowel disorder, call us at 888-229-7408.