Concquer UC, that's quite a speculation you're making....as if IBD syptoms likely weren't as bad back then as it's become...each person (then and now) has it differently and I'm sure that if you could ask president Kennedy how he'd rate his colitis, it would be a 10 on a scale with 10 being the worst....check out this link...
http://www.pbs.org/newshour/bb/health/july-dec02/jfk_11-18.html John Kennedy was sick from age 13 on. In 1930, when he was 13, he developed abdominal pain. By 1934 he was sent to the Mayo Clinic where they diagnosed colitis or it was called colitis.
The 34th president of the United States, Dwight D. Eisenhower, suffered from Crohn's disease and underwent an emergency resection in 1956. That sounds like he had it pretty serious to me.
It's becoming more prevalent now because there are more people now and even worse "toxins" now than before.