 Erosive stomatitis probably secondary to methotrexate even though the medication has been used for ten years without any problems.  Methotrexate may produce an erosive stomatitis and enteritis after such a use. The patient also may have an enteritis that at this point may have become more quiescent as she notes that she did have some diarrhea about the time her mouth problem developed. She has had no diarrhea today, however. She has noted no blood in her stools and has had no episodes of nausea or vomiting.  