Hi Fancsali,
A treatment effect is an uncontrollable oily discharge that can occur 24 to 72 hours after going over in your intake of fat. The oil that you see in the toilet when you go to the bathroom is the oil that is being excreted by alli. The oil can come out separately or be mixed in with your bowel movements so you may not always see it there.
Let me know if you have any other questions,
Betty Kovacs, MS, RD