Senna Safety

Can you tell me what Senna is and if it has any warnings associated with it?

There are several types of senna. The most common forms are senna leaf and senna pods, obtained from several species of Cassia, most commonly Cassia augustifolia, known as Tinnivelly senna, and C. acutifolia, known as Alexandrian senna. There are also the Chinese senna (C. tora) and American senna (C. marilandica).
The leaf and pods have much the same laxative properties. They are used to treat constipation.
According to "Bartram's Encyclopedia of Herbal Medicine" (available from Richters), senna is contraindicated if inflammatory bowel disease is present, such as ulcerative colitis or Crohn's disease, or in cases of appendicitis or if there is abdominal pain of undetermined origin. Bartram goes on to say that if used correctly, there are few side-effects.