[Sigmoid motility stimulated by luminal distention. Changes in the motility response in constipation by the slowing down of left colonic transit].

The aim of our study was to develop a new technique of sigmoid manometry using standardized luminal distensions and to compare patterns of colonic motility following distension in normal subjects and in constipated patients. Eight subjects without colonic disturbances and 8 constipated patients with delayed transit time of the left colon as shown by radiopaque markers were investigated. Sigmoid motor activity was recorded by measuring pressure in a distending latex balloon placed at 25 cm from the anus. Inflations were maintained during 250 s and separated by 60 s recovery periods of deflation. Volumes of air (V) were increased until the patient reported abdominal pain (VMT). For each distension level, the resistance to distension of the bowel wall evaluated by the baseline adaptative pressure (P) and the contractile activity (A) quantified by planimetry of the active contractile activity (A) quantified by planimetry of the active contraction waves superimposed to P were assessed. In normal subjects, VMT was 147 +/- 9 ml. P increased linearly with V (p less than 0.03) up to 4,336 +/- 876 Pa. A increased with V until VMT/2 reached the maximum of 389 +/- 72 Pa*; for higher volumes A decreased significantly with to 166 +/- 46 Pa for VMT. Reference to controls, the constipated patients had a decreased VMT (61 +/- 4 ml). P increase at VMT (5,084 +/- 753 Pa) and A maximal value (387 +/- 176 Pa) were not different.(ABSTRACT TRUNCATED AT 250 WORDS)