title: Ulcerative colitis: Natural history--an optimistic message from Norway.
authors: Laurent
authors: L
authors: Peyrin-Biroulet
authors: Jean-Frederic
authors: JF
authors: Colombel
mesh_terms: D002908:Chronic Disease; D003093:Colitis, Ulcerative / Q000453:epidemiology* / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D009664:Norway / Q000453:epidemiology; D011379:Prognosis; D012307:Risk Factors