One can speculate that suboptimal anastomotic perfusion due to (1) a history of cardiovascular disease (which also caused CKD in this patient), (2) ongoing local inflammation (probably a residual disease or recurrence of the former complicated diverticulitis or associated with intestinal dysbiosis) as well as (3) a chronic inflammatory state (reflected by elevated serum CRP levels) may have predisposed this patient to formation of a fistula adjacent to the anastomosis from a small anastomotic leak. Here, CRP is linked to diverticulitis.