Enema Q- How to reach different parts of the bowel?

Hi, I'm new to enemas- just started three days ago, with one raw garlic enema per day. Initially I only got like 1/4 C in for a whole half hour of trying, but I've been working my way up to more.
I am starting to be able to retain a higher amount each day I try again, but whenever I get a substantial amount in, I get strong cramps that I can't fight through for very long despite massaging, headstands, etc.
Does anyone have tips about how to retain more, and also how much/how long I need to retain to reach different areas of the bowel? I suspect either a parasite/candida infection that I'd like to reach and try to kill off.