CAN A BLOOD TEST DIAGNOSE IBS?

As physicians and gastroenterologists, we frequently encounter cases that elude objective evidence of an organic basis of symptoms, thereby leading to the diagnosis of a “functional bowel disorder,” among which irritable bowel syndrome (IBS) is the most common. These diagnoses are somewhat disappointing for us as clinicians and are clearly quite frustrating for the patient, whose expectations of finding a “true cause” for their symptoms vanquish as each diagnostic test returns “negative or normal.” Nonetheless, it is clear in the minds of all of us that organic, systemic, or metabolic diseases (inflammatory bowel disease, celiac disease, thyroid dysfunction, or gastrointestinal cancer) may also be accompanied by IBS-like symptoms and that these disorders need to be carefully excluded. In this respect, one should consider alarm features and perform blood tests to exclude anemia, inflammatory diseases, and particularly celiac disease, which is fourfold more frequent in individuals fulfilling the Rome criteria for IBS than in controls (see Chapter 22).