My Husband Has Facial Ticks And Essential Tremors. He Does

My husband has facial ticks and essential tremors. He does not take medication for them as they seem to all have very sedating side effects. He recently had diarrhea and took an Imodium. He was very surprised to find that the tremors and facial ticks went away for most of the day. Is there something in that drug that would cause that? Or is it related to some similar drug that is used to help tremors?