The propagation pattern of individual pressure waves in the gastroduodenal area in IBS is unexplored. We performed antroduodenojejunal manometry on 26 patients with IBS--13 with diarrhea predominant IBS (IBS-D) and 13 with constipation predominant IBS (IBS-C)--and 32 healthy controls. Neuropathic-like motor abnormalities were found in 38% of the patients with conventional manometric evaluation. With high-resolution analysis additional abnormalities were observed in the majority of the patients, with increased frequency of retrograde pressure waves postprandially in both IBS subgroups and in phase II in IBS-D. A correlation between subjective gastrointestinal symptoms and the frequency of retrograde pressure waves in phase II in IBS-D was demonstrated. Motility indices and the number of long clusters were also higher in patients compared to controls. To conclude, an abnormal propagation pattern of individual duodenal pressure waves in IBS patients was demonstrated and found to be related to symptom severity in diarrhea-predominant IBS. High-resolution analysis adds information to standard manometry.