Irritable bowel syndrome (IBS) is one of the most common diagnoses made by healthcare providers. Yet the majority of patients with IBS are undiagnosed. The study by Sayuk et al. allows insight into the characteristics of different patient groups, e.g., with and without a formal diagnosis of diarrhea predominant IBS (IBS-D). We discuss the questions raised by this study regarding the importance of making a confi dent diagnosis, conveying it to patients and their implications for clinical practice. Am J Gastroenterol 2017; 112:900-902; doi: 10.1038/ajg.2017 Abdominal pain and diarrhea are the leading gastrointestinal (GI) symptoms prompting ambulatory visits in the United States with more than 27 million ambulatory, emergency department, and hospital outpatient clinic visits per year. Abdominal pain and diarrhea are also common leading GI diagnoses in the ambulatory setting, with "abdominal pain" being the most common (over 16.6 million per year) and "diarrhea" the ninth most common (over 2.6 million per year). Interestingly, the diag noses of abdominal pain and diarrhea are more common than the diagnosis of irritable bowel syndrome (IBS; tenth most common diagnosis with 2.4 million diagnoses per year) ( 1 ). Th e fact that these diagnoses are so oft en made does not come as a surprise when considering the high prevalence of GI symptoms in the general population. Although epidemiological data are scarce ( 2 ), the available numbers indicate that a signifi cant portion of the US population-42% of adults ( 3 ) and 23% of children and adolescents ( 4 ) -experience GI symptoms that correspond with at least one of 20 functional GI disorders (FGIDs), including IBS. However, more than half of the individuals with functional bowel symptoms do not seek medical care for their symptoms ( 5 ).Th ese individuals are oft en referred to as non-patient individuals with FGIDs.In this issue of the journal, Sayuk et al. report their fi ndings from an online survey conducted in 1,924 individuals from a general US population who had previously participated in various surveys and had indicated having GI symptoms. Individuals were excluded if they reported having habitual constipation or rectal blood loss in the month prior to participating in the survey. Th e authors found that 1,094 (56.9%) of the respondents met the Rome III criteria for IBS-D and received a formal diagnosis from their health care provider. Th e other 830 (43.1%) individuals fulfi lled the Rome III criteria for the disorder (IBS-D), but had never received a formal diagnosis. Furthermore, over half (53%) of these undiagnosed individuals have never spoken to a physician about their abdominal symptoms, and therefore, have never received a formal diagnosis ( 6 ). Given this considerable proportion, the question arises what factors drive individuals experiencing abdominal symptoms compatible with IBS to consult their health care providers about these symptoms? While most studies have repeatedly shown that abdominal symptom severity is an important determinant in...