undiagnosed intestinal parasites

[savetheearth]

I have been suffering with intestinal parasites for over a year and have not been able to get a diagnosis despite multiple stool exams, blood tests, and a colonoscopy.  I am desperate for appropriate treatment and my 3 doctors do not believe anything is wrong and are not concerned.  I am wondering if anyone has ever heard of my symptoms.  I understand humans can be infected with worms or arthropods.  I have something that causes frequent diarrhea and constipation, loud intestinal noises, vague nausea and general gripeyness.  I first noticed about a year ago that I could feel something crawling out of my anus.(that's when I first saw my doc).  she treated me for pinworms & I took all precautions, but had no relief.  That got progressively more frequent and I began noticing that I could feel something crawl out & crawl on my skin & eventually bite my skin in various places on my body.  When I am bitten I have a reaction where I get hot & flushed & sweaty.  Apparently whatever it is is microscopic because I have never been able to see any type parasite.  I almost always pass these rounded white hardened little balls (1-2mm) in my stools but I have not been able to find any information about any parasite that has eggs that big.  Could this be some kind of worm that has microfilaria?  I have developed a nearly constant right sided headache now and I am wondering if there is any relation.