Irritable bowel syndrome (IBS) is a gastrointestinal disorder characterized by abdominal pain or discomfort that is associated with a change in the form or frequency of bowel movements. It is a functional disorder, meaning symptoms are caused by changes in how the gastrointestinal tract works.
Dr. Brooks Cash, professor of internal medicine at the University of South Alabama College of Medicine and a gastroenterologist with USA Physicians Group, said IBS is an important condition because it is incredibly common – affecting one out of five people in North America.
“IBS is not a trivial topic,” he said. “Patients with IBS have the same physical health-related quality of life (HRQOL) scores as patients with diabetes and lower physical HRQOL scores than patients with depression.” In addition, psychological HRQOL scores in patients with IBS are lower than in patients with chronic renal failure and can be so severe as to raise risk of suicidal behavior.
Dr. Cash said IBS is not a life-threatening condition, but it certainly can make patients miserable. “We have patients who have to rearrange their lives because of their symptoms,” he said. “They avoid certain types of food because they find that those types of foods can be triggers to their gastrointestinal symptoms, and they may even avoid social interaction.”
Most patients with IBS have moderate symptoms. However, Dr. Cash said one out of five patients has severe symptoms that make a huge impact on their quality of life.
The causes of IBS are multiple and incompletely understood. IBS symptoms can result from a recent gastrointestinal infection or can occur in those who have bacterial overgrowth in their small intestine. Some people develop IBS for no known reason.
“IBS has a bad reputation,” Dr. Cash said. Many people think it’s a stress-related disorder and that it is psychologically mediated. “That can be true,” he said, “but it is not the only cause of IBS. The majority of patients with IBS actually do not have significant psychological comorbidities.”
People with functional gastrointestinal disorders such as IBS are often found to have GI motility disorders as well as extra-gastrointestinal symptoms such as chronic back pain; chronic headaches/migraines; chronic pelvic pain; and chronic fatigue syndrome – all of which have a common theme of pain and discomfort. According to Dr. Cash, one of the common themes for people who suffer from IBS is the presence of a visceral and/or somatic hypersensitivity.
The Rome Criteria is commonly used to make an IBS diagnosis. The Rome Criteria are:
Recurrent abdominal pain or discomfort at least 3 days/month in the last 3 months associated with 2 or more of the following: improvement with defecation, onset associated with a change in frequency of stool, onset associated with a change in form of stool.
Dr. Cash said IBS should not be a diagnosis of exclusion. “It’s really a positive diagnosis that we can make based on clinical criteria and symptoms.” Although testing is not necessary to diagnose most patients, people with the following alarm features may need to undergo diagnostic testing: worsening abdominal symptoms, advanced age, blood in stools, anemia, unintentional weight loss, anorexia, or family history of organic gastrointestinal disease.
Although there is no single cure for IBS, diet and lifestyle changes may help with mild or intermittent symptoms. “The more active you are, the greater your gastrointestinal motility is, which can help patients with their symptoms,” he said. “In addition, dietary therapy – such as a low FODMAP diet or low-carbohydrate diets such as the Atkins diet – can improve patients’ symptoms. The problem is that these diets are very difficult to adhere to.”
For patients that have more severe symptoms, pharmacotherapy may be an option. The main goal of pharmacologic treatments for IBS is to treat the symptoms. The cardinal symptom – abdominal pain/discomfort – can be treated with antispasmodics (which relax the muscles) or antidepressants (which are used to help raise the pain threshold, not because the patient is presumed to be depressed). Anti-diarrheals or laxatives can be used to treat the primary bowel dysfunction, and probiotics or antibiotics are often used to treat bloating.
Dr. Cash said additional therapies are being developed that are geared to result in overall improvement in symptoms as opposed to just treating some of the individual symptoms of IBS.
According to Dr. Cash, a good patient-provider relationship is extremely critical for successful results with IBS. “It’s important to identify important symptom triggers and work with your provider to address them,” he said. “It may take some trial and error and can be a long process. IBS is a global condition that affects so much more than the gut.”
Dr. Cash recently gave an overview of IBS at the December Med School Café lecture. To view the lecture in its entirety, click here.