After having a colonoscopy 3 months ago they found no signs of pouches 2 weeks ago you had an emergency operation for diverticulitis Is this possible?

Yes, it is possible to develop diverticulitis after a colonoscopy that showed no signs of diverticula. Diverticula can form over time, and the condition can develop suddenly due to factors such as changes in diet, increased pressure in the colon, or other underlying health issues. The absence of pouches during the colonoscopy does not guarantee they won't develop later, leading to diverticulitis.