Assertion: ulcer | /r/RelatedTo | gastrointestinal disease
Facets:
Source sentences:
text: Although there are many causes of oral ulceration, recurrent oral ulceration has relatively few causes, most commonly aphthous stomatitis, but rarely Behçet's disease, erythema multiforme, ulceration associated with gastrointestinal disease, and recurrent intra-oral herpes simplex infection.