A laxative is a substance or medication that is used to stimulate bowel movements and promote the evacuation of the bowels. Laxatives can be taken by mouth, applied directly to the skin, or administered rectally in order to soften stools and increase the ease of defecation. They work by either increasing the water content of the stool, stimulating nerve endings in the intestines, or altering the muscle contractions in the colon. Laxatives are commonly used as a short-term solution for constipation but should not be used excessively without consulting with a healthcare professional first.