IBS with constipation, functional constipation, painful and non-painful constipation: e Pluribus…Plures?

IBS with constipation (IBS-C) and chronic constipation (CC) can be difficult to distinguish clinically. The Rome III criteria create mutual exclusion between IBS-C and CC, based on the presence of abdominal pain, which is a defining criterion for IBS-C. Previous surveys found that up to 45% of CC patients have abdominal pain and other IBS features. A Spanish general population study proposes a subclassification of patients with CC based on abdominal pain and other features of IBS. As the Rome criteria evolve, these and other observations provide the basis for further efforts in discerning key features of IBS-C and CC.