What Are The Symptoms Of IBS?

Hello, I ve been to the doctors about 5/6 times now. On first appointment, I was told to wait a month, see if my pain died down and then come back. I did, the pain got worse, nothing helpful or good came out of it. On my second appointment, the doctor poked my stomach around, I explained how the pains were in my left abdomen, that I noticed mucus in my stools and had sore pains in the morning/night. I was told to give it another 2 weeks and come back if it was still there. He asked if I was stressed, I said no, I m at university, 18 years old, no stress in my life, no issues that would cause stress. I went back in 2 weeks and I saw another doctor, she said it could be IBS after I said it was getting worse, she prescribed me Mebeverine and Fexofenadine (for my hayfever). She said to take them for 2 weeks, then come back and see if they re helping. I ve only been taking them a week and my symptoms are getting worse. I ve had what looks like plastic lining in my stools, more mucus, inconsistencies, some are clumped together, some are small, lots of small droplets, most recent was very dark with a large lining sheet inside the stool, the largest it s been. I see food that hasn t been digested (such as pea s) and the pains are now all throughout the day. To make it more odd, I am a homosexual, my partner has also now started to have similar problems, he is seeing mucus in his stools. Previous to this, my partner had worms, on a first occasion, we took a Mebendazole tablet, then and I stayed for a week in his house and my partner (weeks on) still had irritation around his anus and worms in his stools, so we both took a worming tablet, again Mebendazole. I have already done a urine test (for Chlamydia), a blood test and a stool sample, which all came back as okay; I was puzzled how my stool samples came back normal, I have taken many photos, all showing them not okay (I can provide, if somebody wants to see what I m attempting to describe). Me and my partner were both virgins and did have unprotected sex, but should I be worried about something? I was planning on going back the doctors and explaining this, saying how my partner is having the same symptoms and pains (except he has constipation, bloating, bad wind) whilst I do not. From the pains, I tend not to eat a large breakfast, I rarely have lunch and I only have my main meal. Could this be IBS (a fluke for both of us to have it) or an intestinal bacterial infection, shall I repeat a stool sample? I strongly appreciate all help, I have had this for what I can remember being the best part of 5 months, at least. Regards, Kirk