Its ok, we all get diarrhea sometimes. Just buy some supplies like air freshener and a toilet brush and it will all be fine. Plus if your all friends it should be fine. Just put yourself in their shoes and ask yourself 'would I really be that bothered if someone was having a hard time on the toilet?'. If your worried about being to loud just take your phone in with your and blast tiktoks or something on full volume, its very common for people to be scrolling on their phones while they're on the toilet. It might be awkward for a little bit but soon enough you'll get used to it and the people you're living with will become just like siblings.