Fluid factor. Some people experience a greater incidence of constipation due to dehydration. Your body needs water to make stool easier to pass. So drinking more cranberry juice can decrease your dehydration and help with constipation.

Is cranberry juice a good laxative?

A moderate amount of cranberry juice has no known harmful effect, but an excessive intake may have a laxative effect.

What not to drink when you are constipated?

It is important to note that some liquids can increase the risk of dehydration and make constipation worse for some people. For example, those who are prone to constipation should limit their intake of caffeinated sodas, coffee, and alcohol.