I recently had surgery on both knees, 6 weeks apart. I tripped and fell on Easter Sunday. Instead of falling on my knees, I twisted my body around so I'd land on my backside, which I did. Hard. The pain is almost gone, but now when I bear down in the bathroom, there is blood. Fresh, really red blood. I am not constipated, and the blood doesn't appear to be in my stool, more like it's in the cavity somewhere. I am 51 years old, disabled, extremely overweight (5 ft 9 in, 260 lbs). I am currently taking wellbutrin to quit smoking (3rd week). Could it be the medication or is it more likely that I have torn something inside?