High-resolution analysis of the duodenal interdigestive phase III in humans

To study the spatial organization of the propagating pressure waves of duod enal phase III, we performed fasting antroduodenal high-resolution manometr y with a 16-channel catheter in 12 healthy subjects. The phase III pressure waves diverged in an anterograde and retrograde direction from the start s ite of each pressure wave. The pressure waves maintained this configuration as the activity front moved distally in the duodenum. The start site of th e pressure waves moved gradually to a point approximately 12 cm (median) di stal to the pylorus and remained at this point for about 40% of the phase I II time before moving further distally. The length of retrograde pressure w ave propagation increased to 6 cm (median) as the pressure wave origin move d aborally to a point 10-14 cm distal to the pylorus, and then decreased wh en the origin of pressure waves reached the distal end of the duodenum. Bid irectional pressure waves dominated in both retrograde and anterograde acti vity fronts. Three pressure-wave mechanisms behind the duodenal phase IV we re observed. Isolated pyloric pressure waves were absent during late duoden al phase III retroperistalsis. Thus, a number of new features of the duoden al phase III-related motility were observed using high-temporospatial resol ution recordings.