Help Identifying parasite and proper treatment. Considering Humaworm

Back in early august of this year I began experiencing severe itching upon bowel movements and only during bowel movements. Never at night. I began to suspect a parasite. Also this just began happening one random day. I was fine one day then having rectal problems the next. Also my stool was very slimy with red tomato skin like chunks. Less than a week later I passed what seemed to be a bunch of white larvae but I wasn't too sure so I decided I would just wait and go to the hospital if it were to persist. That next Monday at work I passed what was indesputabely a worm of some sort. It was about half an inch long and white in color and very alive as it was moving around. It appeared rather plump and was pointy on both ends. This sent chills up to my neck and II went to the emergency room panicked. They were of no help. I sat there all day and gave them a stool sample as well as blood. Both came back negative. I wasn't imaging things. I KNOW what I saw. So finally after arguing for a while the doctor gave me albendazole which I had hoped would work but the symptoms persisted. Since then I have never seen the thing again in my stool and have submitted numerous stool samples along with a colonoscopy/endoscopy which revealed nothing. I am at whits end trying to identify and treat this problem. It has been a while and the symptoms have subsided a little but they are still there. Today my stool takes many different forms, I'm passing what looks like dead short worms but I'm not sure if it's just undigested food/ fiber and upon taking probiotics I have been experiencing a rectal/groin/butcheek rash. Could this be some sort of parasitic die off from the probiotic?Anytime I eat it feels as though the food is just slipping right through me and I'm also experiencing excessive gassiness. Way more than ever before and my bowl movements usually smell particularly fowl. Also I'm always so tired later on in the day. I always need a nap when I get home from work which was never the case in the past. After the colonoscopy the doctor diagnosed me with IBS gave me probiotics and metamucil, then sent me out the door. It's been several months and I'm just so confused and have many questions that hopefully I can get the answers to here. First off I've considered the possibility that the albendazole successfully eliminated the parasite but the infection triggered IBS because there was nothing in my colonoscopy BUT on the flip side I'm considering the possibility that this parasite was missed because the camera does not fit in the small intestine. Which parasites specifically live in the small intestine and what could be used to eliminate them? I'm considering taking a holistic approach such as humaworm. Could this work to give me my freaking life back?!? This is so frustrating and upsetting because one day I was normal and then the next BAM. I have no idea where I could've gotten this or how this happened. It is worth mentioning however that roughly two months prior to this starting I adopted a puppy who wasn't house broken and was constantly cleaning his cage which put me in direct contact with his feces. Please give me any advice, suspicions, and insight. Also tell me your humaworm experiences. Can I be cured?