[Correlation between pressure phenomena and transport of solids in the human left colon]

The aim of this study was to correlate the pressure phenomena with the transport capacity of the left human colon. Studies were performed in 6 volunteers with a terminal left colostomy for low rectal neoplasia. Our method is original and it is based in the introduction into the colonic lumen of a 2 cm diameter litle deformable solid ballon (Sham-fecaloma) with 3 perfused catheters in the vicinity. This ballon is connected by a semirigid probe with a displacement measurer. Our results show that there are a two kinds of segmental motor phenomena: those which provoke a solid displacement (Displacement Motor Phenomenon-DMP) and those which do not (Non Displacement Motor Phenomenon-NDMP). Both are a pressure increase but the DMP show a pressure gradient in the aboral direction (P = 0.003) and the NDMP in the oral direction (P = 0.003). The DMP provoke a quickly solid output but with a short (X = 4.2 cm). In this way, we can say that segmental contractions are propulsive if in the biohydraulic system there is a pressure gradient in the distal (aboral) direction. If these gradients are not established or they are in oral direction there is no progression neither backward movements. During the periods without pressure activity also there is a slow displacement in the aboral direction (35%). These movements without pressure phenomena may be explained by the tonic contractions (stretching and shortening) not detectable by the conventional manometric systems.