People who have bulimia nervosa often overuse laxatives to get rid of food eaten during a binge eating episode. Laxatives speed up the passage of stool through the body by irritating the lining of the intestines.

Laxatives do not reduce the number of calories the body absorbs from food. But laxatives may cause a person to lose weight because they increase the amount of water eliminated through the intestines. Overusing laxatives can cause a person to lose too much water and certain body chemicals, such as potassium and sodium, that are needed for keeping the muscles and heart healthy.

Symptoms of laxative overuse include:

• Constant or repeated bouts of diarrhea.
• Belly pain and swelling.
• Swelling of the ankles or hands.
• Weakness or extreme fatigue.
• Kidney problems.