Weight loss from enemas comes from a combination of removing up to several pounds of fecal matter and clearing out a build up of toxins that contribute to weight gain. Coffee enemas, in particular, are popular, as the coffee washes waste away with antioxidant effects. Enemas are believed to stimulate, balance and clear reflex points from the colon to the rest of the body.
The main theory behind enema-based weight loss is autointoxication, the belief that undigested waste matter builds up excess mucus that produces toxins that get reabsorbed and distributed via the body's circulatory system. Fatigue, weight gain, low energy and headaches are attributed to these toxins.
WebMD attributes the health benefits and potential weight loss of enemas less to the flushing of toxins and more to the effect of good bowel health on the rest of the body.
However, people should always exercise caution when using enemas for weight loss purposes. Abusing laxatives can be a sign of an eating disorder. Frequent use leads to an upset in electrolyte balance, resulting in muscle cramps, tremors, spasms, arrhythmia and cardiac arrest. Over time, enemas can stretch the colon until it becomes too weak to generate the muscle spasms needed to pass fecal matter.