Ive suffered with IBS for 7 years and nothings worked. I read codeine is good for IBS-D so i'm going to ask doctor about it when see him. I'm going to a wedding in about a month so will be drinking alcohol. I know you shouldnt combine alcohol with pain killers. The weddings on a Friday so if I took codine up till Thursday and didnt take it on the Friday would I be ok to drink alcohol or will it still be in my system?