They do not "crawl" out, they "flush" out. I used to be scared too. Believe me, better out than in. It was scary to see what was in my colon. (I still do not like checking my stools while cleansing, but I check them anyway.)
I have learned so much over the last series of cleanses about how blocked up my colon and liver was. And, from what I read and recently experienced, you cannot cleanse the liver unless you get rid of the parasites first.
It is gross, but, you will feel so much better afterwards. It is a small price to pay in comparison to the alternatives, like life threathening surgery or medications with side effects.
I trust you will overcome your aversion for the greater good -- a clean colon!