Senna (Cassia Senna) is used to relieve constipation. It sually clears bowel movements within 6 to 12 2 hours. hours It is also used to treat constipation to clear bowel before diagnostic test. Do not take Senna alone continuously for more than I week and do not make it a daily habit. 2 or 3 tablets of Senna and 1 or 2 tablet of evening gives better results Triphala taken.