Ulcerative colitis (UC) moved from isolated 19th-century case reports to one of the two defined forms of inflammatory bowel disease (IBD) over roughly 150 years.^[1] Samuel Wilks reported the first case of non-infectious colitis in 1859. Most historical reviews credit William Hale White’s 1888 case series with establishing the term ulcerative colitis.^[1][2] Before the 1932 description of regional ileitis by Crohn, Ginzburg, and Oppenheimer, colonic Crohn’s disease and UC were often confused with each other. This means 19th-century physicians could not have distinguished UC from Crohn’s disease.^[1][3] Corticosteroids, introduced in the mid-1950s, sharply reduced the historically high mortality of severe UC. Anti-TNF therapy, starting in 2005, opened the era of biologic and small-molecule therapy.^[4][2]

• 1859: Samuel Wilks published the first case describing a distinct, non-infectious inflammatory disease of the bowel. This set it apart from the infectious diarrhoeal illnesses common at the time.^[1][2]
  • Looking back, Wilks’s index case had ileal involvement, and it is now thought to have been Crohn’s disease rather than classic UC.^[1]
• 1888: William Hale White’s case series is usually credited with bringing the term ulcerative colitis into the medical vocabulary.^[1]
  • Some secondary sources still credit Wilks with the term in 1859, so attribution remains disputed.^[2]
• Late 1800s: Sporadic case reports from Europe and the United States built up, and UC changed from an anecdotal finding into a recognizable diagnosis.^[1][5]
• 1909: A symposium at the Royal Society of Medicine in London reviewed 317 UC cases collected from seven London hospitals between 1888 and 1907. This was the first collaborative study of the disease. It recorded only two to three admissions per hospital per year.^[1]

• 1932: Crohn, Ginzburg, and Oppenheimer described regional ileitis as a separate disease. This established the two-disease model of IBD.^[1][3][5]
• Before 1932, colonic Crohn’s disease and UC were often grouped together. Older case series should therefore be read with care.^[1][3]

• 1939: Chopra and Ray described 120 UC cases in Kolkata, India.^[1]
• 1956: The first UC case report from China was published. This reflects the later appearance of IBD in developing regions.^[1]
• Kaplan and Windsor describe four stages in the global evolution of IBD:^[1]
  1. Emergence: the Western world in the late 19th and early 20th centuries; developing countries today.
  2. Acceleration in incidence: newly industrialized countries.
  3. Compounding prevalence: Western regions today.
  4. Prevalence equilibrium: projected for the future.
• UC is now a global disease. Incidence is rising fastest in newly industrialized countries in Asia, Latin America, and Africa.^[6][1] For current incidence and prevalence figures, see Ulcerative colitis epidemiology and demographics.