This way we only open a little tiny bottle. If your baby is struggling to go, prune juice is a safe and effective way to get their. How To Prepare Prune Juice For Constipation In Toddlers How long does it take for prunes to work as a laxative? How long does it take for prune juice to work in babies . Although you shouldn’t use prune juice for babies under 6 months, you can try diluting one tablespoons of it in water. When giving prune juice to an infant, the mayo clinic recommends trying 2 to 4 ounces at a. The results of the study suggested that drinking 125 milliliters, or about half a cup, twice a day works as an effective laxative, at least in cases of mild constipation. Click to see full answer. Aug 20, 2020 at 6:05 am. 1 tbsp virgin olive oil; October 2010 i give ds 1/2 oz prune juice and 1/2 oz water in the am and it has taken anywhere from a. How long till prune juice takes effect? For adults, drink 4 to 8 ounces of prune juice each morning to stimulate a ...