Definition: Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.
Input: Abstract: A patient with severe chronic gastritis and duodenitis that clinically and endoscopically disappeared after an intestinal revascularization procedure is reported. Chronic intestinal ischemia appears to be a cause of gastritis as seen in this patient.

Duodenitis