The reoccuring problems you described are probably not directly caused by parasites, altho they may be or have been part of the cause. The symptoms are caused by overgrowths of bacteria and yeasts in your gut eating the partly digested food eaten and producing loads of gas and some toxins, too.
Although your situation may be different, in me I seem to carry some 'bad' bacteria in my bile system. I can get rid of the overgrowths in my intestine by using Clark's iodine, hydrogen preoxide, digestive enzymes, probiotics and in the past, turmeric and cayenne or other spicy spices but whenever I eat more of the pesky organisms come out with the bile and grow again in the intestine. In addition to following a gluten free diet I have to avoid any food or spice which causes inflammation in the small intestine and have had to do and continue to do many Liver Flushes.
I'm finding that using Hoarhound tea with honey is helping the gas/bloating problem.