What are the Risks I am Taking if I take Flagyl while Suspecting I may have Pancreatitis??

Hello there; my family is really laying the pressure on me to take the 2nd course of Flagyl prescribed to me by my doctor. He prescribed the 1st course of 250mg 3x a day for 10 days BEFORE he performed a Flex Sig and found nonspecific proctitis or receiving my stool samples. I did felt a little better, but the symptoms of proctitis are slowly returning over the last 3 day that I stopped the medications. He prescribed another 7-day course w/ 500mg this time and I have been holding off for a few days b/c he prescribed this to me before he recieved my stool sample results (Campylobacter, C.Diff, Shiga, E. Coli,Leuokocyte stain,  ova/parasites, Salmonella and Shigella... all negative). I should note that I had the stool samples privately done, b/c of no insurance, and sent it to him a day after I called him with the complaint of my symptoms returning and him prescribing the 2nd course.

I fear he prescribed the Flagyl to me still believing I have some significant bacterial/viral infection before noticing my stool results, and I may most likely not have one so now my attention is turning towards my liver/pancreas. Wouldn't these pills significantly hurt me, especially now that he prescribed double the dosage??