Do Flagyl 400mg Tablets Have Adverse Effect On Ulcerative Colitis?

hi doctor, i m in 7th month of my pregnancy, last week for 3 days i noticed white discharge along with terrible back pain, now my dictor has advised me to take 3 tabs flagyl 400mg for 3 days each & 1 syscan. i am also suffering from ulcerative colitis, will these medicines worsen my colitis problem.