[Collagen diseases and gastrointestinal bleeding].

The main lesion of the collagen diseases involves blood-connective tissue, so every collagen disease is a accompanied by gastrointestinal bleeding to some degrees. The concept of systemic vasculitis had been confused, but recently, the criteria for each disease has been established. In addition to these vasculitis, antiphospholipid syndrome, amyloidosis, NSAIDs, steroid and secondary infection caused by the use of immunosuppressant are the candidates for the cause of gastrointestinal bleeding in the collagen diseases. In this paper, we described concisely about the gastrointestinal bleeding in SLE, RA, and systemic vasculitis.