Can I Take Antibiotics To Cure Diverticulitis After Having Had Whipple Procedure For Bile Duct Tumor?

I had Whipple procedure for bile duct tumor on May 30th 2012. I developed infection due to my body rejecting black thread stitches inside me that wouldn t resolve. There were three of them but doctor said he could only get to two of them to remove and left the third one saying it would eventually dissolve or work its way out. I continued to develop one problem after another Since that time along with my CA19-9 being at 637 despite all scans and test coming back negative for cancer. I am now told I have diverticulitis and am given antibiotics an that this can cause this high number in CA19-9. My question os this possible? developing pneumonia then rhuematoid arthritis I have had fluid. buildup around both lungs and had drained several times