Dios mio!

So my Italian is pretty spotty and I am the only person in the group who speaks Italian. I'm trying to translate for people and have noticed that people will ask you for something and as soon as you start to ask the store owner, bus driver, etc the question (which sometimes takes a bit since as mentioned above-my Italian is spotty) they start to ask them in English. Which then makes the job that much harder because they clearly speak no English and now I am yelling my spotty Italian over their English and it's just not getting results. One extremely awkward example of this happened today. Someone needed some medicine to take care of an issue. So I went into a pharmacy with this person and was trying to think of the most discrete way to ask for some medicine. So I'm going in Italian " um I don't know what it's called but we call it immodi----" before I can finish the sentence the person blurts out "diarreah" really loudly. I was dying. I don't understand why people ask for my help if they are just going to go rouge.