White defined spots in stool and more.

[Remmik]

I have been the picture of health until now. I'm a 35 year old male with Mexican roots 6 feet tall and 209 lbs. I have been watching my cholesterol the past two years (was 219 now 187). I have noticed, for some months now, very defined but non-similar spots in my stool. They are about the size of rice or smaller. They are not from what I eat since I have changed from one food to another throughout this time to see if it is that. The color of stool changes but the spots are still there. For the most part they are sparse. A couple every square inch but I had it were they were 10 per square inch twice now. I was also getting upper abdominal twinges/light pain on the right and left for a few weeks straight. Also, a slight sore spot in middle front under rib cage. That hasn't happed for a few weeks now but still get a slight twinge on occasion.  After a few weeks of all this I got (out of nowhere) got severe hives (I have researched them and they are hives...as well as showing pictures to my doctor to confirm). I was getting deep tissue hives as well (lip swelling, throat felling weird and inside eye corners swelling shut. I did some research before going to the DR. and felt it might be a parasite. He ordered a stool sample. I gave samples in three different colored bottles. All tests came back negative. The Allegra he prescribed works great at stopping all histamine reactions but they come back as soon as a few hours pass when I don't take it on time (although mostly deep tissue and not severe). I also feel a lot of weird pressure (almost strained like) in the rectum especially when I'm in need of going number 2 but mostly gone when I don’t have to go. At times when I get up from sitting in one position for some time it is very uncomfortable almost painful, in the same area, when I stand up. This last visit yesterday puzzled my doctor after the negative reports so he is sending me to a GI doctor and ordered a CT scan with double contrast. I can’t find anything on the net with all these symptoms and can’t find anything (except for parasites) about these white spots. Any ideas?