Fan Xie Ye commonly known as Folium Sennae or Senna Leaf is the leaf of Cassia angustifolia or Cassia acutifolia, which is a dwarf shrub belonging to the family Leguminosae. It is a medication used to treat constipation and empty the large intestine before surgery, which first appeared in The Effect of Fan Xie Ye Property. Bitter, cold, large intestine meridian entered. Actions. Relax bowels with purgative.