Gastric accommodation in functional dyspepsia

Clear indications of antral dysfunction such as antral widening, weak antral contractions, and delayed gastric emptying are seen in approximately one-third of patients with functional dyspepsia. However, abnormal intragastric distribution is also often seen, and it appears as if dysfunction of the proximal stomach, especially its ability to accomodate to a meal, is a more prevalent finding in functional dyspepsia than antral dysfunction. Impairment of proximal gastric accommodation may constitute a primary abnormality in these patients, a view supported by the concomitant improvement of proximal gastric accommodation and symptom relief after the administration of GTN. Nevertheless, we suggest that functional dyspepsia is best understood by applying a bio-psycho-social model. Psychologic factors like hyperresponsiveness and neuroticism and personality factors like somatization contribute to stress and sustained CNS activation, which seems to encompass a chronically suppressed vagal tone. The consequences of the latter might be as follows: impaired receptive and adaptive gastric relaxation with impaired accommodation and intragastric maldistribution including abnormal filling of the antrum. Discomfort elicited by meals is in part ascribed to increased wall tension. Visceral hypersensitivity may constitute an additional mechanism. A vicious circle arises when the sensory input is amplified by a hyperresponsive mind. Lack of coping leads to sustained brain activation and persistence of the ailment. Clearly, the abdominal symptoms constitute only a part of the real problems of patients with functional dyspepsia. In the complex interaction between central and peripheral mechanisms, gastric accommodation to a meal plays a role. Its importance, however, is not yet clearly established.