Two hypotheses were tested: first, the postcibal motility disorders occur in both the antrum and small bowel of systemic sclerosis patients with gastrointestinal symptoms; second, that dysmotility may result from a neuropathic stage in this disease. Upper gut perfusion manometry (3 h fasting, 2 h fed) was performed and compared with data from similarly studied healthy laboratory controls (n = 15). Only 1 of 8 scleroderma patients had an interdigestive motor complex during the 3-h fasting period [0.1 +/- 0.1 (SEM) for systemic sclerosis vs. 1.4 +/- 0.16 (SEM) for controls, p less than 0.05]; 2 other patients had fasting duodenal incoordinated bursts of phasic pressure activity in the duodenum or proximal jejunum. Distal antral motility index [MI = In (sum of amplitude x number of contractions + 1)] was lower (12.4 +/- 0.5, p less than 0.01) than that in controls (14.4 +/- 0.14); both the amplitude and frequency of antral pressure activity were lower (p less than 0.05) in systemic sclerosis. The intestinal fed pattern was characterized by reduced amplitude and frequency of contractions in 6 patients; 2 patients had excessive phasic or tonic small bowel pressure activity, or both. Thus, antral hypomotility is present in most symptomatic scleroderma patients; proximal small bowel postcibal motility is characteristically reduced; a minority of such patients have incoordianted fasting or postcibal hypermotility suggestive of a neuropathy. Manometry identifies the type and region of dysmotility in systemic sclerosis; our results suggest that there are neuropathic and myopathic stages of the upper gut involvement in systemic sclerosis.