Worms can travel anywhere in the body..when the colon is severely damaged and meds/herbs do not absorb.
They cannot be killed succesfully and they run from the poisons.
That is why some developed protocols to target the whole body at once.
Some parasite warriors have said that starting and stopping the meds leads to further problems..that is why you are not suppose to stop until the infection is clear.
Others say not to even mess with them..but work on the whole body..or some say..why kill just the fish and do not clean the tank?