I've done some reading and you can get HSV in the rectum and possibly the colon, very rare (colon) however I have had UC (ulcerated colitis) for 6 years and my doc says it's just my immune system out of wack. If I get a cold sore and take Valtrex my stool become less painful. Right now, I have bloody skin, skinny stools and pain! when I go to the bathroom, this is nothing new for me. It's been 6 years! and I cry a lot because sometime I will just go to the bathroom and it will be bloody, skin like stuff. A usually diarreah. My doc says it's just UC and she doesn't believe it would be Herpes ...and I have tested positive for 1 & 2 (never a outbreak vaginally) only cold sores and the test I had was a blood test. I sure just want to take Valtrex for a while and see if my UC improves, I've only taken it for maybe 4 or 5 days. How much and how long can I take it? Is it really toxic to the liver? I worry about that too. Can you help me please. Anyone have herpes of the rectum and can it go up further? I have it at the rectum and left side of colon (ulcers)