ABSTRACT

IBS has been defined as a functional bowel disorder in which abdominal pain is associated with defecation or a change of bowel habit, with features of disordered defecation and distention. The criteria for diagnosis have evolved from the Manning criteria in 1978 to the Rome I criteria in 1988. The latter were revised to Rome II criteria in 1998 (Box 12.1; Thompson et al., 2000).