Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Stop using senna and call your doctor at once if you have:
rectal bleeding;
no bowel movement within 12 hours after using senna; or
low potassium level--leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling.
Constipation is the most common side effect of senna. Less serious side effects may be more likely, and you may have none at all.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Senokot side effects (more detail)
