Literature reports indicate that the incidence of delayed gastric emptying (DGE) is higher after pylorus-preserving pancreaticoduodenectomy (PPPD) than after conventional pancreaticoduodenectomy (CPD), but DGE is traditionally diagnosed from patient-reported subjective sensations. Our clinical radiological experience suggests higher rates for physiological DGE post-CPD. We therefore sought to quantify rates of subjective DGE (sDGE, based on patient complaint) verses objective DGE (oDGE, based on scintography) post-CPD and post-PPPD. Contractile motility of post-PPPD residual stomach was also studied. For 21 PPPD and 33 CPD patients between October 1997 and June 2000, sDGE and oDGE data were collected preoperatively, on postoperative day 14, and 6 months postoperatively, with cholescintography for pylorus ring competency on postoperative day 14. The incidence of sDGE was higher for PPPD (42%) than for CPD (15%) at 14 days, with zero sDGE for both at 6 months. The incidence oDGE was higher for CPD (91%) than for PPPD (76%) at 14 days, with a 6-month incidence of 4.7% in PPPD but approximately 33% for CPD. Solid-phase emptying in PPPD showed that residual stomach retained partial gastric emptying function at 14 days but not at 6 months. Cholescintography showed abnormal pylorus closure function in 2 of 21 PPPD patients but was not related to DGE. Literature reports of higher DGE incidence post-PPPD are true only for subjective symptoms. Radiological measurement of oDGE shows that both CPD and PPPD manifest approximately 80% incidence of DGE in the early postoperative period. At 6 months, approximately 33% of CPD show persistent oDGE. We concluded that (1) the concept of DGE should distinguish between subjective and objective symptoms; (2) loss of distal stomach mechanoreceptors in CPD reduces patients sensation of oDGE, producing "silent" DGE; (3) both CPD and PPPD have high and approximately equal rates oDGE; (4) the previously unnoticed silent oDGE in CPD may contribute to the higher rates of ulceration and related morbidity in association with CPD.