Written by Dr. Sarah Ballou and Dr. Trisha Pasricha
How is IBS diagnosed?
IBS is diagnosed through a set of clinical criteria that your doctor reviews based on your medical history. A hallmark of IBS is chronic abdominal pain related to your stool. Your doctor may do additional studies if you have other symptoms like bleeding in your stool or unintentional weight loss. Scientists, including our team at BIDMC, are keen to develop tests that identify the abnormality specific to each patient with IBS in the future.
What causes IBS?
Irritable bowel syndrome is a constellation of symptoms with multiple etiologies. Researchers like those in our group are working hard to understand its many potential causes, which we hope may ultimately lead to targeted treatments. In some cases, there is an infectious trigger—such as a bout of food poisoning or even COVID, after which people’s bowel habits become altered. Studies have found that infections like these can cause long-term inflammation in the gut, which we think drives IBS. Other studies have linked stress and trauma early in life to IBS. These factors can influence communication between the brain and the gut and change how people’s bowels move as well as how they perceive and process pain. There are other factors involved including the microbiome and genetics—and how these interplay with food and our environment is a major area of research.
What does it mean if all tests are normal?
It can be confusing to have bothersome gastrointestinal symptoms with normal results on medical studies. As mentioned above, IBS is diagnosed via a set of clinical criteria based on your medical history and description of symptoms. This is because most medical tests do not detect the abnormalities that we know to be present in IBS. These can include an altered microbiome, disruptions to the neurons inside the colon, and gut inflammation and permeability. These changes aren’t picked up by standard imaging studies or biopsies of the surface of the colon such as those that you might get during a colonoscopy. Many researchers like ourselves hope to one day develop a test that can safely and accurately diagnose IBS.
Is this all in my head?
No, your symptoms are not all in your head. We hear from many of our patients how their symptoms have been dismissed in the past as purely anxiety or stress. Gut-brain communication has a lot to do with your brain, but the symptoms are not ‘imagined’ or related to mental health issues.
Signaling between the brain and the gut happens automatically and 24 hours per day. This signaling happens via the nervous system, the microbiome, and the endocrine system. Your brain’s role is to receive messaging from the gut (e.g. signals of pain or discomfort) and to communicate information about your environment and your emotions to the gut. When this communication becomes altered, as is the case in IBS, the brain can receive exaggerated signals of pain and can also send exaggerated signals to the gut. When this happens, patients often experience increased pain/discomfort as well as alterations in bowel habits. For this reason, IBS is categorized in a class of disorders called disorders of gut-brain interaction, or DGBI.
How is IBS treated?
There is no single treatment or cure for IBS because of how differently it manifests— and why—in each individual. Getting the right therapy tailored to your needs is important. Options include medication, dietary changes, gut-brain psychotherapy, and more. Our experts at BIDMC can help guide treatments based on the latest evidence and your own medical history.