Hi Rodney. I just finished 4-1/2 Mos. of Rocephin. Up to 2-1/2 mos. had lots of GI problems but were corrected with good probiotic. I had to go through 3 different ones until i found one that worked. Last month of rocephin, i wasn't even taking any probiotics and GI was good as it could be. I guess my body just got used to it.