Hi Shroom - parasites don't have red blood cells so those RBCs are your very own and are coming from the colon. Here's an interesting article
Peer-Reviewed Journal Articles by Dr Vasquez on "Reducing Pain and ...
Peer-Reviewed Journal Articles by Dr Vasquez on "Reducing Pain and Inflammation Naturally" published in Nutritional Perspectives of the American Chiropractic Association ...
I think that a visit to a gastroenterologist is the thing to do. You need to rule out protozoa - amoeba especially and other infective organisms. The Dr can take rectal swabs to look for parasites and yeasts/bacteria. Some of these organisms are protected by biofilm that needs to be digested away for successful treatment.