Ciliophora actually has an anal pore, which is used to excrete waste.
Excretion in unicellular protist by: aloka andrew
Unicellular protist first of all have a very reduced size. This means that they do not require any special organ of excretion as in multicellular animals. Therefore excretion is by simple diffusion across the cell membrane. For example, excretory gases leave the cell via the membrane likewise to other metabolic waste.