Diverticulitis, Colitis and Crohn’s have become an epidemic in the last 60 to 80 years. Before that, they basically did not exist.
There are over 190 countries on this planet. Nearly all of the colitis, diverticulitis and Crohn’s deaths (gastroenteritis mortality rate) come from fewer than 20 of these countries and over 80% of them come from only 7 modern “Westernized diet” countries. These countries are: (UK, USA, CAN, AU, DE, NZ and SA).
Billions of people in the less developed countries with less “modern style” diets have few digestive disorders (gastroenteritis) of which, colitis is a member. These digestive disorder “free” countries include Asia and Africa. (see above link)