Autonomic dysfunction in gastrointestinal motility disorders.

The records of 113 consecutive patients with a suspected gastrointestinal motility disorder referred between January 1988 and July 1991 were retrospectively reviewed. The aims were to identify the prevalence of autonomic dysfunction in those with or without associated neurological disease and to determine the diagnostic value of testing for autonomic dysfunction. All patients had gastrointestinal manometry (3 hours fasting, 2 hours fed), 94 of 113 underwent testing of sympathetic adrenergic and cholinergic function and cardiovagal cholinergic function. All tests were scored in a standard manner. There was a significant (p < 0.05) but modest (r = 0.28) rank correlation between autonomic and motility scores. This correlation was stronger (r = 0.67, p = 0.01) in diabetic patients. The number of patients in each group with autonomic dysfunction was as follows: irritable bowel syndrome nine of 33, idiopathic upper gastrointestinal dysmotility six of 21, diabetes mellitus nine of 13, identified non-diabetic neurological syndromes six of nine, postvagotomy or abdominal surgery three of 11, and myopathic pseudo-obstruction two of seven. Autonomic testing is useful in the assessment of autonomic involvement outside the gastrointestinal tract. Logistic discriminant analysis showed that autonomic function testing did not add to the diagnostic value of motility tests in distinguishing between patients with and without irritable bowel syndrome, although a slight improvement was indicated for identifying neuropathic dysmotilities. Thus, the aetiological role of general autonomic dysfunction in irritable bowel syndrome and idiopathic and postvagotomy dysmotilities deserves further study. The addition of autonomic function tests does not add substantially to the diagnostic accuracy of clinical, radiological, endoscopic, and manometric techniques in most patients referred for evaluation of a suspected motility disorder.