It has nothing to do with pooing and everything to do with feeding your stomach. You’ll get that hollow gnawing, churning feeling in the stomach that won’t go away. There are easier ways to fast . If you took homemade juices during the week and drink only water during the weekend, you would do better. Drinking black tea will dehydrate you. If you drink green juice, you’ll get rid of that acetone smell you talk about. You will loose weight and you will keep your body flooded with nutrients. You’ll be able to drive and work ( office environment) without being a danger to yourself and others.