Can diverticulitis and diverticulitis cause complications with diabetes?

Yes. Diverticulitis, by definition, is a bacterial infection arising from a hole in the colon. Any infection may complicate the management of diabetes.
Converse. The converse is true - diabetes can potentiate the complications of diverticulitis.
If you have. Divericulitis with fever and elevated WBC with or without an abscess, this could cause your diabetes to get out of control and cause severe, life threatening complications. If you have an infection and diabetes, the infection needs to be properly diagnosed and treated promptly not one or 2 days later.