Senna leaf is an herb that has been used for many years to relieve constipation. This herb irritates the lining of the colon, stimulating the bowels to contract and forcing stool out of the body. The consequences of ingesting this plant should be considered when contemplating taking it as a laxative.
Senna leaf acts as a laxative, relieving constipation for many. As with several other laxatives, senna leaf should not be taken long term (no more than 2 weeks) since the bowels can become dependent on this herb to work.
Senna leaf can also cause cramping. The tea can be quite powerful, causing strong intestinal contractions. Cramping can sometimes be very painful, and if you've taken the tea before work or an outing with friends and family, you may need to excuse yourself.
Senna leaf works diligently to clear out your intestines -- even when your body is not in the best position to do so itself. Diarrhoea can occur during this process, potentially causing dehydration and electrolyte imbalance. Electrolytes are minerals such as sodium, potassium and calcium that have important functions in the body.
Short-term diarrhoea (up to three days) is usually not very harmful, as dehydration and electrolyte imbalance don't have much time to set in. Long-term diarrhoea (more than three days) can lead to significant electrolyte imbalance, which can cause several health issues including pneumonia, confusion and abnormal heartbeat. Dehydration (loss of large amounts of body fluid) can set in, which is cause for immediate treatment by a physician.
Constipation is a common problem during late-term pregnancy, since the foetus presses up against the intestines. The National Institutes of Health states that senna leaf is possibly safe during pregnancy and breast-feeding as long as it is used for a short period of time. Some sources warn that senna leaf has the ability to cause uterine contractions which can potentially lead to miscarriage. It is best to consult your physician regarding the safety of using this herb during pregnancy.
Long-term use of senna leaf has also been associated with liver failure. The reasoning behind this correlation is that anthraquinone (a component of senna) may be broken down in the intestines, forming a substance that is toxic to the liver in some people and causing liver damage.