What You Should Know About IBS

Between 25 and 45 million people in the United States have irritable bowel syndrome (IBS), which is characterized by abdominal pain or discomfort, and altered bowel habits. It’s a staggering number for a syndrome with unknown origins. 

To mark IBS Awareness MonthDavid Wan, M.D.assistant professor of Medicine  at Weill Cornell Medical College, Cornell University, and assistant attending physician  at NewYork-Presbyterian Hospital/ Weill Cornell Medicine (WCM)discusses the condition, its sub-types and symptoms, and the resources available for IBS patients.  

How would you describe irritable bowel syndrome? 

IBS is characterized by symptoms of recurrent abdominal pain associated with diarrhea or constipation. Patients will have changes in their bowel form or frequency that is tied to abdominal pain. They will also frequently have bloating. 

How is IBS diagnosed, and about how long does it typically take for a patient to be diagnosed with IBS? 

IBS can be diagnosed and treated fairly rapidly—often within one visit. To diagnose IBS, a gastroenterologist will take a careful clinical history showing the symptoms in the absence of alarm features (alarm features include weight loss, blood in the stool, whether the age of onset of symptoms is greater than 50, family history of inflammatory bowel disease or colon cancer) that lasts more than six months 

The gastroenterologist also would perform a physical examination and minimal diagnostic testing, which can include blood tests to rule out celiac disease and a stool test to rule out inflammatory bowel disease. There is no need for a colonoscopy unless a patient needs it for screening purposes. Sometimes conducting that more comprehensive search for other causes of the symptoms can sometimes delay the diagnosis, but it generally doesn’t take long.  


IBS is often described as a disorder of gut-brain reaction. Is this a new way of thinking about the condition? What is the gut-brain dynamic that causes IBS? 

Yes, this is a new way of framing the disease, and it highlights the complex interplay between the gut and the brain. There are signals that go in both directions and will affect the nature and severity of symptoms. People with IBS seem to be more sensitive to activity in the gut related to food, bacteria, etc. In turn, when people are anxious or stressed, it can manifest itself with symptoms in the gut.  


Are there genetic components to the syndrome? 

There may be, but it has not been clearly worked out. Some studies suggest that, if you have a relative with IBS, you're more at risk for IBS.  Nevertheless, the underlying gene pathways, genes and functional variants linked with IBS remain unknown.  


Is IBS a sign of other, more serious conditions or associated with other health problems?   

IBS is associated with conditions such as small intestinal bacterial overgrowth, fibromyalgia, and psychiatric disorders such as depression and anxiety. But generall, the symptoms of IBS (abdominal pain and altered bowel habits) are non-specific and rarely due to other, more serious conditions like celiac disease, inflammatory bowel disease, or colon cancer. These conditions are unlikely in the absence of alarm symptoms.  

What are the different types of IBS, and how are they treated? 

There are four types of IBS:  

  • IBS-C - mostly constipation 
  • IBS-D - mostly diarrhea 
  • IBS-M - relatively equal mix of constipation and diarrhea 
  • IBS-U - unable to be determined 

Treatments for IBS should be tailored to each patient's IBS subtype.   

In general, diet plays a major role because certain foods can trigger symptoms. Specific diets, such as the low FODMAP diet have been shown to improve symptoms. This diet involves eliminating and re-introducing certain foods to determine which foods are best to avoid. Incorporating soluble fiber and peppermint oil also can help patients.  

For patients with IBS-C, medical options can include lubiprostone, linaclotide, and plecanatide. For younger women without heart issues, tegaserod can help. 

To address the diarrhea and pain associated with IBS-Dwe sometimes prescribe rifaximin, eluxadoline, or tricyclic antidepressants. 

Antispasmodic medications can be helpful to ease abdominal cramps and, for constipation itself, polyethylene glycol (i.e. Miralax) can help.  Probiotics have limited data to support their use but are often given with some anecdotal success. 

Gut-directed psychotherapies and complementary therapies also can be helpful. These can include cognitive-behavior therapy (CBT), hypnosis, mindfulness, and mindfulness-based stress reduction. 

What resources does WCM have available to IBS patients? 

Many of our providers specialize in IBS, and the Center for Advanced Digestive Care at Weill Cornell Medicine also has dedicated GI nutritionists. At the Integrative Health and Wellbeing Program, patients can learn about complementary therapies that may be helpful in managing IBS.