Irritable bowel syndrome is the most frequent functional disorder of the digestive system. Patients with irritable bowel syndrome have motor disorders not only in the colon, but also in other parts of the digestive tract such as the oesophagus and small intestine; however, it is not known whether the stomach is also involved. We used a radiolabelled mixed solid-liquid meal (technetium-99m for the solid component, indium-111 for the liquid component) to study gastric emptying of solids (GES), liquids (GEL) and indigestible solids (GER) in 50 patients diagnosed as having irritable bowel syndrome (30 with predominant constipation and 20 with predominant diarrhoea). GER was measured by counting the number of indigestible solids remaining in the stomach 4 h after they were swallowed. In patients with irritable bowel syndrome, GES and GEL were slower than in control subjects (P<0.05). GER was normal in all patients except for two women. Thirty-two patients (64%) showed delayed GES, 29 (58%) delayed GEL, and 2 (4%) delayed GER. Among patients with irritable bowel syndrome, GES was slower in those with predominant constipation than in those with predominant diarrhoea (P<0.05); GEL and GER were similar in both groups. Gastroparesis was found in a large proportion of patients with irritable bowel syndrome, suggesting the presence of a more generalised motor disorder of the gut.