Morbid obesity surgery can be defined as any type of surgery intended to provide dramatic weight loss for morbidly obese patients.

There is a difference between "morbidly obese" and simply, "obese." The distinction is important when considering the possibility of morbid obesity surgery, as morbid obesity surgery is usually considered inappropriate for those who are simply obese.

Morbid obesity is defined in a variety of ways, such as: a) weighing twice your normal body weight; b) being more than 100 pounds over ideal body weight for a given height and gender; c) having a body mass index (BMI) greater than 40 (BMI will be explained below); d) having a BMI of 35-39.9 with significant problems such as obstructive sleep apnea, diabetes or cardiac disease.

Body Mass Index gives a general estimate of weight relative to height. It is calculated by dividing weight (in pounds) by the square of your height (in inches). A BMI of about 18-25 is considered normal.

Morbid obesity surgery is usually taken to mean one of several surgeries that: a) restrict food intake ("restrictive" type); b) reduce food digestion and absorption ("malabsorptive" type); or c) both of these. The two most common types of morbid obesity surgery are gastric bypass and lap banding.

Gastric bypass surgery is a combination-type of morbid obesity surgery. In this type of morbid obesity surgery, a small portion of the stomach is stapled off from a much larger portion of the stomach. Only the smaller "pouch" (about two - two! - ounces) receives food. This small pouch is then connected directly to a much lower part of the small intestine, thereby "bypassing" normal digestion and absorption. This type of morbid obesity surgery has the greatest overall success rate.

Lap banding is another type of morbid obesity surgery, in which a small pouch is "banded" off by a fancy, inflatable rubber band that squeezes the stomach into two compartments. Only the smaller, upper portion can accept food. Absorption is normal. The advantage of this type of morbid obesity surgery is that the size of the pouch can be adjusted after surgery by filling or emptying the band with water through a small tube placed under the skin.

A third, and drastic, type of morbid obesity surgery, is called "biliopancreatic diversion." In this type of morbid obesity surgery, a small portion of stomach is stapled off and then connected directly to the large intestine, bypassing nearly all digestion and absorption. This is a severe form of morbid obesity surgery and therefore should be considered only after ruling out other types of morbid obesity surgery.