Only if parasites
are so big that he can see them, and if they are inside colon.
Ascaris is usually inside small intestine and inside bile ducts, and pin worms are very small, not easy to see, unless they are very manny.
Tapeworm is big and can bee seen, but colonoscopy is very expensive and traumatic procedure, so I would suggest parasites
cleanse. It is cheaper, no trauma, and most herbs use actually support health and support liver and bowel function.