Thanks for posting on HCM,
is a safe procedure and complications are rare. Such complications may include colonic perforation, bleeding, infection, abdominal distension, postpolypectomy coagulation syndrome
, splenic rupture, small bowel obstruction and medication effects. Incidence of any of the above mentioned complications is less than 1%.
The pain you are presently experiencing might not be due to the colonoscopy but rather due to the diverticulitis
(with microperforations it is very possible that the pain could have persisted despite treatment). At this point, it might be necessary for you to see a visceral surgeon for reevaluation and further management (which might require surgical intervention).
Hope this helps