a little over a week ago I engaged in anal sex. protection was used and the condom did not break either time. we used lots of lube due to him being very large. It wasn't painful to me at all. there was a very tiny bit of blood on the toilet paper after we finished and I pushed all the lube out, but not enough to cause any concern. my poop and bowel movements were normal up until 6 days after. On the 5th day after I developed a stomach ache. My poop was normal except for when I wiped this gooey light green mucus came off on the toilet paper, theres no weird smell it just smells like poop. On the 6th day I felt like I had to go a lot, the first few times they were normal, but then I had green poop and one out of the 3 times I had green poop some was floating. The next day my poop was back to normal but since then I have had very little green mucus on the toilet paper twice and all other times a little bit of yellow mucus on it with a few times no mucus at all... its been 8 days later and I still have the lower stomach pain, but on a scale of 1-10 its like a 2 sometimes a 3. I do not know why this is occurring and I don't believe it could be an STD, the only thing that was unprotected was receiving and giving oral. I do have IBS with bloating but my IBS doesn't cause me to have diarrhea and I was lactose intolerant as a baby, but ive drank milk constantly everyday for years and have had no problems. Im sorry for all the information but I just wanted to give as much information as possible to get a very good answer. Im really worried. I honestly feel like ill never be able to have anal sex again and will never ever be in a relationship with anyone again if this is something serious. This is only my second partner ive ever did anything sexual with. Im so scared that maybe it could be an STD despite my doubts and that it could be a very serious one that will ruin my life forever. HELP ME!!