Hi lygray, loose stools are likely being caused by this unhealthy diet and any medicine you give your rabbit is just a temporary fix. What Lola really, really needs is a healthy, balanced diet with lots and lots of fiber in the form of timothy hay. I realize your father just does what he pleases, however can you give him healthier treats to give her like fresh sprigs of mint, papaya tablets, bunny cookies, pieces of fresh fruit? I would not dose your rabbit with the kaopectate, immodium etc. a lot of those products contain aluminum, which is not healthy. Do you have any quick or rolled oats in the house? Try a tablespoon of them instead. I’m also wondering the same thing K & K asked, what did the vet prescribe?
Also, from what you have written I am a tad confused if Lola is yours or his. If Lola is in fact yours, is it possible to move her to your room where you can keep a better eye on her and her diet? Have you had your father read information on rabbit diet at all? It may help. I find that if you offer someone a few education materials, they do eventually get around to reading it and they turn things around. I think that perhaps by you telling him that she could die (even though it is the truth) he believes you are joking because he has been doing this for some time and he sees no immediate danger because she is there the next day and the next day after that. Do you pay the vet bill? Perhaps make him start paying the vet bill because he is the reason why she has to go to the vet. Sometimes it is effective when they are affected in the wallet.