B

Modern guidelines emphasize that irritable bowel syndrome (IBS) should be diagnosed positively using Rome symptom-based criteria and limited testing for alarm features, rather than by exhaustively excluding every other disorder. In other words, IBS is no longer regarded as a pure “diagnosis of exclusion” [Henderson & DiPalma, 2011, PMID 21297534; Lacy et al., 2021, PMID 33315591].