It is very common practice to use laxative for constipation relief. Laxatives are either medicines, drugs or foods which are taken to induce bowel movements. Laxatives are also called purgatives. Main job of laxative is to push out or eliminate any undigested food in the large intestine.
How do Laxatives work?
To understand how laxatives work you need to know two things. Stool which are hard are difficult to eliminate. Stool is pushed out using a contraction in the bowel. This is 
called peristaltic movement and discussed in the Help with Constipation article. Laxatives may be oral or in suppository form.
Lubricant laxatives work by covering the surface of the stools thus preventing water loss. Doing this ensures that the stool remains soft and hence easier to eliminate.
Some laxatives also soften the stool by drawing fluid into the stool from the surrounding tissues and cells this softening it.
Another type of laxatives are known as stimulant laxatives which cause the bowel to squeeze or contract to move the stools out. These try to induce the peristaltic movements artificially. These laxatives should only be taken rarely on advice of doctors.
Bulk-forming laxatives draw water into the stool to create large soft stools creating a bigger mass and triggers the peristaltic movement. It is essential to drink plenty of fluids. These are considered to be very safe laxatives and can be taken on more regular basis.
Stool softeners are another type of laxatives which work by incorporating additional water and fats in the stool, making it easier to move along.
Precautions with Laxatives
- Too much frequent intake of laxative are not good as they can be habit forming.
- Too much dose of laxative can cause diarrhea.
- If you are undergoing treatment for some medical condition it is better to consult your doctor before taking a laxative as it may interfere with the effectiveness of the drug.
- In case you suffer from any allergies then please check the contents of the laxative before taking it.