Irritable Bowel Syndrome (IBS)

What is irritable bowel syndrome?
Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that affects the muscles and nerves of the intestine and can lead to a variety of gastrointestinal symptoms. Depending on which subtype of irritable bowel syndrome you have, IBS can be associated with one or a combination of symptoms including constipation, diarrhea, abdominal bloating, abdominal cramping, abdominal pain, increased gas and/or stool urgency. There are three subtypes of irritable bowel syndrome; constipation-predominant irritable bowel syndrome, diarrhea-predominant irritable bowel syndrome and mixed-type irritable bowel syndrome. The mixed type is characterized by cycling between constipation and diarrhea. Irritable bowel syndrome is more common in women but affects men as well. It is a very common diagnosis in patients referred to gastroenterologists for their bowel symptoms.

What causes irritable bowel syndrome?
Irritable bowel syndrome is called a functional gastrointestinal disorder, since it is caused by abnormalities in intestinal functioning. One abnormality in IBS patients is the way the intestinal muscles coordinate to move stool and gas through the intestine. This is termed intestinal motility. If the muscles do not coordinate optimally, intestinal symptoms can result. Another abnormality in intestinal functioning is the way our intestinal nervous system senses gas and stool movement through our intestine. In IBS, the nerves in the intestine are often oversensitive compared to those in patients without irritable bowel syndrome. Finally, another abnormality is the way our brain interacts with our gastrointestinal system. The gastrointestinal system is unique from other organs in that there is a large network of nerve connections between our brain and our intestines. Therefore, emotional distress can affect intestinal function, and intestinal function can lead to emotional distress. All of these abnormalities have been used to target specific treatments for the different subtypes of irritable bowel syndrome.

What are the symptoms of irritable bowel syndrome?
Irritable bowel syndrome can lead to a variety of gastrointestinal symptoms, which can include constipation, diarrhea, abdominal bloating, abdominal cramping, abdominal pain, increased gas and/or stool urgency. Generally, these symptoms may occur for months or even years.

How is irritable bowel syndrome diagnosed?
Irritable bowel syndrome is diagnosed through a well-defined, well-studied set of criteria called the Rome criteria. These criteria were established by a group of gastroenterologists who have a passion to study and improve the treatment of irritable bowel syndrome. Based on a patient’s age, symptoms and physical exam, further testing to confirm the diagnosis may include colonoscopy, upper endoscopy, CT of the abdomen and pelvis, breath testing, stool studies and/or lab work.

What is the treatment for irritable bowel syndrome?
A key component in the treatment of irritable bowel syndrome is acceptance of the diagnosis and working with your gastroenterologist to find a treatment plan. Irritable bowel syndrome can be controlled by following a healthy diet and practicing good stress management in a large majority of those who suffer from this diagnosis. For those with more moderate to severe irritable bowel syndrome, there are several therapeutic options that can be considered. To alter the consistency of stool and movement of gas and stool through the intestine, laxatives (Miralax, magnesium, Amitiza, Linzess) or antidiarrheals (Imodium, Questran, Lomotil, Lotronex) may be used. To alter the sensitivity of the intestinal nerves and relax the intestinal muscles, antispasmodics (Bentyl, Levsin) may be used as well as tricyclic antidepressants (amitriptyline, nortriptyline, despiramine) and/or serotonin reuptake inhibitors such as Celexa. For those who have ongoing difficulty with emotional distress, depression, or anxiety, traditional antidepressant/antianxiety medications (Zoloft, Paxil, Wellbutrin, Effexor) may also be prescribed by your primary care provider or psychiatrist.

In addition to the above medical therapies, alternative therapies such as behavioral therapy, modern hypnosis, acupuncture, or mind-body therapy can also be considered.

When to seek medical advice
Please contact your health care provider if you note a new change in your bowel habits, rectal bleeding or weight loss, as these can be signs of a more serious condition. If IBS is significantly impacting your quality of life, this is also an indication to seek medical advice or consider a change in treatment.

Additional Resources
“Master your IBS” by the American Gastroenterology Association
“Making Sense of IBS” by Brian Lacy, PhD, MD
www.theromefoundation.org (Rome foundation website)
www.iffgd.org (International Foundation for the Functional Gastrointestinal Disorders website)