This is an item pointed by Dr. Liwei Wang:
Current OAE term 'duodenal ulcer AE' (OAE_0000895) has an alternative name 'peptic ulcer AE'. However, peptic ulcer may include duodenal ulcer and other ulcer (stomach ulcer):
http://www.webmd.com/digestive-disorders/digestive-diseases-peptic-ulcer-disease