Digenea
In Digenea, the small tube-like structures (or tubules) end in flame cells, which propel the waste to a posterior bladder. This bladder then excretes the waste through an excretory pore. The excretory system of Digenea does not focus on removing water, unlike the urinary systems of other Platyhelminthes. Rather, it excretes a significant portion of the physical waste of the food as well.
Cestoda
Cestoda (also known as Tapeworms) have similar urinary systems the Digenea. However, as the Digenea's waste is known to contain a substantial portion of physical waste, Cestoda tend to have very diluted waste. This is a result of the Cestoda's attempt to balance the water level within its body. Because it is in an osmotic enviroment, excess water often enters, and must be forced out through excretion out of the proglottids.
Trematoda
Trematoda is a class of flatworms that is notorious for its parasitic behavior. In order to excrete waste, members of Trematoda use two kidney-like structures known as nephridiums which filters waste into a bladder. Waste leaves the bladder to be excreted from pores on the end of the animal via metenaphrida.