Measurements of duodenogastric reflux of bile and gastric emptying of a 5 per cent glucose liquid test meal have been made in 8 patients with combined gastric and duodenal ulcers and the results compared with those found in 21 patients with a diagnosis of uncomplicated duodenal ulceration. It was not possible to demonstrate any differences between the two groups of patients in respect of these studies and it is suggested that gastric stasis and duodenogastric reflux may not be important factors in the aetiology of combined ulcer disease.