Irritable Bowel Syndrome
MARK S. SCHWARTZ
SAMI R. ACHEM
Irritable bowel syndrome (IBS) is one of the most common disorders encountered by gastroenterologists. Yet treatments focused on gastrointestinal (GI) factors are often unsuccessful, and psychophysiological and psychosocial factors that contribute to the experience of pain and to pain behaviors are often not taken into consideration (Drossman et al., 2000b). GI tests are typically normal in IBS (Drossman et al., 2000b; Van Dulmen, Fennis, & Bleijenberg, 1996). This chapter discusses issues and information sought or needed by practitioners and students of applied psychophysiology who evaluate and treat persons with IBS, and the rationale for including relaxation, biofeedback, and other nonmedical therapies as part of multicomponent treatment for IBS.1 (As in other chapters, italics on first use of a term indicate that the term is included in the glossary at the chapter's end.)
The diagnosis of IBS rests primarily on symptoms. There is no biological test or marker indicative of this disorder. Investigators use symptom-based criteria to define IBS. One of the most widely employed and recognized criteria sets was developed by Manning, Thompson, Heaton, and Morris (1978). They noted four common symptoms among those with IBS: (1) pain eased after bowel movement, (2) looser stools at the onset of pain, (3) more frequent bowel movements at onset of pain, and (4) abdominal distension.
More recently, a group of international experts gathered in Rome at two separate meetings to provide a contemporary definition of this disorder, taking into consideration new research information and striving to improve clarity (Thompson et al., 1999). The results of the most recent meeting have resulted in a new proposed consensus, summarized as follows:
at least 12 weeks or more, which need not to be consecutive, in the preceding 12 months of ab-
dominal discomfort or pain that has two out of three features:
1. Relieved with defecation; and or 2. Onset associated with a change in frequency of the stool; and or 3. Onset associated with a change in form (appearance) of stool. (Thompson et al., 1999, p. 1144)
The above are in the absence of structural and metabolic abnormalities to explain the symptoms.