Certain kinds of eye drops can make people poop, but I do not think that you can use eye drops as laxative. When a kind of eye drops are taken by someone as laxative, he will poop more, but at the same time, the ingredients in the eye drops can also cause great damage to body such as diarrhea and even dehydration. Some chemicals in the eye drops are very poisonous. Some people even use eye drops to commit murder. Besides, according to the instruction, eye drops are drugs for external use and cannot be taken through mouth. As the name suggests, it can only be applied to eye problem. If you have constipation, you should buy laxative in the nearby pharmacy.