Figure 2.

Different models to explain functional bowel/disorders of gut-brain interaction. (A) Rome I considered the functional bowel disorders as different and independent entities. (B) Later, Rome II-Rome III recognized that these disorders could overlap between the different functional bowel disorders. (C) Rome IV now considers that bowel disorders exist on a continuum rather than independent disorders. Adapted and reproduced from Whorwell et al³⁵ with permission from Rome Foundation, Inc. IBS, irritable bowel syndrome; FC, functional constipation; FDr, functional diarrhea; C, constipation; D, diarrhea; M, mixed.