Sentence:  The writer states that: (1) during the past decade <WSD>protology</WSD> has come to include diseases of the colon, and that the extension is beneficial inasmuch as it encourages and provides for a better diagnosis, and for a more thorough search after etiology. 
Meaning of the word marked with <WSD> tags:  (medicine) A branch of medicine specializing in diseases of the colon and rectum