Normal iron levels however hgb is low 13.6. What this mean? Bening colon polyps removed. Diverticulosis diagnosed from most recent colonoscopy.

Polyps can bleed. While polyps and diverticuli can bleed, the bleeding from the latter is dramatic and scary, while the bleeding from the former is very slow and not noticeable overtly. Your situation sounds like bleeding from polyps.
Continue workup. You may still be iron-deficient if taking an occasional vitamin-with-iron tablet gives a false-normal serum level. A serum ferritin and some other labs would be in order. A check for thal minor and reticulocyte count may also be appropriate.