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Constipation is a common condition and it can be treated in many ways, such as eating a balanced diet, drinking adequate fluids and taking oral medications, if needed. Senna is an herbal non-prescription laxative that is FDA approved. It is used primarily to treat constipation, but can also be used to clear the bowels before diagnostic tests, such as a colonoscopy. Talk to a doctor before using senna or any herb for constipation.

How Senna Works

Senna is appropriate for use in children over 2 years old, adults and the elderly. Senna laxatives work by increasing intestinal peristalsis, or movement of the intestines. Using chemicals called sennosides, Senna laxatives help keep water in the intestines in order to stimulate a bowel movement, which should occur within six to 12 hours after taking the medication. Available in either chewable tablets or dissolving strips, Senna should always be taken by mouth.

Side Effects

Many people use senna laxatives without experiencing serious side effects, however long term use should be avoided. Senna may cause urine discoloration, but this effect is generally considered harmless. If you experience nausea, vomiting, cramps or diarrhea and they become worse, consult your physician. If senna laxatives are used too frequently, laxative dependence, electrolyte imbalance and loss of normal bowel function can occur. To avoid adverse side effects, always follow label instructions if you are self-treating, and consult your doctor or pharmacist if you have questions.

How to Prevent Constipation

To prevent constipation, eat a balanced, high-fiber diet, drink plenty fluids and exercise regularly. Aim to eat between 25 g and 35 g of fiber each day by consuming high fiber foods such as fruits, vegetables, whole grains and beans. To include more fiber in your diet, follow the 2010 Dietary Guidelines for Americans recommendation to consume 2 1/2 cups of vegetables and 2 cups of fruit each day and make half of your grains whole grain. For adequate fluids, aim to consume at least 8 glasses per day. You may need more, depending on factors such as warm weather and increased activity levels. Fluids are found not only in water, but in juices, teas and soups.


If you experience abdominal pain, nausea or vomiting, be sure to consult your physician. Senna may not be safe for use during pregnancy, especially if taken long term. Finally, use caution if you have diabetes, since senna chewable tablets and dissolving strips contain sugar.