Hi My Name Is Monica. I'm 25 Years Old And

Hi my name is monica. I'm 25 years old and I have been taking Lialda for ulcerative colitis for about 7 months now( since being diagnosed). It's been working fine. Got rid of the mucous and blood in stool and also pooped regularly. But now within the past week or so I've been feeling constipated, hardly passing stool, and in the small amount of stool that I did manage to get out l, it had blood and mucous. What could be going on? Is this known as a flare even while on medication? Please advise! Thank you!