How much prune juice should you drink when treating constipation?

When drinking prune juice to treat constipation, the recommended daily amount is 120 ml; however, this amount may be adjusted based on each individual's bodily response to the prune juice based on body weight and other factors, as reported by Total Health. The high abundance of fiber and sorbitol helps the body to retain water, which increases the moisture content of the stool, allowing it to pass more easily through the body.

Sorbitol is similar to glucose; however, it can only be absorbed by the body slowly. As a result, it has a tendency to hold onto water, which allows it to moisten up the stool.