Are There Any Side Effects Of Taking Chantex For Abdominal Pain?

I have Been chantex for over a month now and after the first two weeks started experiencing severe abdominal pain but I kept taking the chantix today I noticed fresh red blood when I wiped and a little bloody mucus in the toilet but not in the stool could this be caused from the Chantax if so I have no problem not taking it for I haven t smoked in 3 days and have no desire to smoke