Senna Extract

If you have fewer than three bowel movements per week or your stools are harder than usual, you may have constipation, according to the University of Maryland Medical Center. Stress, chronic disease, or certain medications may cause constipation. Inadequate fiber or fluid intake and lack of physical activity can also contribute. If constipation lasts for more than a few days, talk to your doctor about what might be causing it.

Senna may relieve constipation by stimulating the muscles of the colon to push fecal matter through more quickly. It may also help your colon absorb water to soften stool. You may expect a bowel movement within six to 10 hours of taking senna, according to the National Cancer Society. Active compounds in the senna plant, called sennosides, may be responsible for its laxative effect.