We assessed results of examination and treatment of 100 patients with ulcer disease who had undergone Bilroth-1 stomach resection. Chronic disorder of duodenal patency was revealed in 86% of the patients. This condition was shown to play the leading role in the development of post-gastric resection syndrome. Reflux-gastritis was associated with damping syndrome in 66.3% of the patients and with recurrent ulcer in 8.1%. It is concluded that conservative and surgical treatment of post-gastric resection syndrome should be aimed at correction of chronic disorders of duodenal patency.