Can Senna in water cure constipation?

Senna leaves in water has a certain laxative effect, but the active ingredients of drinking water are limited, it is recommended that the decoction.
Senna is the dried leaflets of narrow-leaved senna or sharp-leaved senna of the leguminous plant genus Sambucus. The taste of the medicine is sweet and bitter, and the nature of the medicine is cold, attributed to the large intestine meridian. Clinically, it can be used to treat constipation, ascites and swelling of the limbs caused by heat in the large intestine.
It is forbidden to take it if you are physically weak, pregnant, glaucoma, chronic enteritis or allergic to senna. Allergic people should be careful when taking senna. Senna can be made into tea, but excessive use of senna may cause nausea, abdominal pain and other adverse reactions.
If you need to use senna, please follow the doctor’s instructions, do not recommend self-medication, so as not to delay the condition or cause adverse effects.