OBJECTIVE Delayed gastric emptying (DGE) is the major morbidity after pylorus-preserving pancreaticoduodenectomy (PPPD). Gastroscintigraphy was used to characterize food distribution in the proximal and distal stomach during emptying. METHODS Between October 2000 and June 2003, 20 healthy volunteers and 23 PPPD patients underwent single-phase gastric emptying scintigraphy 14 days after surgery. Scintigraphic studies of the stomach were divided into proximal and distal regions, and the ratio of proximal to distal radiation counts (P/DR) was plotted. Momentary monitor-displayed images were compared to evaluate meal distribution during emptying. RESULTS There were 21 eligible patients, 12 without symptoms of DGE (sDGE-) and 9 with symptoms of DGE (sDGE+). In healthy volunteers the mean P/DR value was maintained at a level of > or = 2.5, and momentary images showed dilated proximal and constricted distal stomach throughout meal emptying. In both the solid and liquid phase tests, the average P/DR value for sDGE- patients was slightly lower than that for healthy volunteers, and momentary images showed early emptying of the solid meal. The mean P/DR value for sDGE+ patients was abnormally low and remained constant throughout the assessment. Momentary images showed significant dilatation of the distal stomach, with constant full size. The odds ratio for the change in P/DR per minute decreased after surgery, especially in sDGE+ patients, indicating a loss of contractility of the distal stomach. At the 6-month follow-up, the P/DR values exhibited a normal decreasing trend but were lower for sDGE+ patients than for healthy volunteers. CONCLUSIONS The P/DR curve provides new insight into normal and pathological gastric function. After surgery, temporary loss of contractility of the distal stomach causes symptoms of DGE.