Gastric bypass surgery (GBS) is one of 4 types of surgical procedures which come under the heading of Bariatric Surgery. GBS significantly reduces the effective volume of the stomach to alter the patient’s physical and physiological response to food. Its objective is to help people who are morbidly obese to lose a substantial amount of weight. GBS accounts for the largest number of bariatric surgical procedures performed.

What is done during Gastric Bypass Surgery?

In GBS, the patient’s stomach pouch is reduced and reattached to the intestines both at the upper end and the midsection. With a diminished stomach pouch, the patient is not able to consume more than 1 or 2 ounces of food at a sitting which results in substantial weight loss without constant food cravings. There are various procedures under GBS all focused on reducing obesity.

Which patient would benefit from Gastric Bypass Operations?

Most gastric surgeons offer this procedure only to people whose Body mass Index (BMI) is over 40 or those who are more than 100 pounds overweight.BMI is a more reliable index since it takes into consideration both weight and height of the individual. Gastric bypass surgery is perceived to be a risky procedure though the mortality rate is only 1 to 2 percent, with roughly 25 percent of recipients returning for treatment some kind of post-operative complication. GBS is used only as a last resort where conventional methods of losing weight have been tried without success. It is the perfect weight loss solution in extreme cases, where failure to drastically reduce weight will place the patient in a life-threatening situation from other conditions like type 2 diabetes, cardiovascular disease, hypertension and similar co-morbid diseases. Surgery to bypass the gastric is performed to counter morbid obesity. It has been proved to be very successful where most patients lose over 100 pounds within a year of surgery. Other benefits resulting from this weight loss operation are enhanced mobility and improved social relations.

What are the various Bypass Gastric Procedures?

There are 3 standard procedures outlined below:

1.      Gastric bypass, Roux en-Y (proximal)

This is the most commonly adopted technique in bariatric procedure followed in the United States. The outcome is that a patient begins to experience a sense of fullness, satisfaction and indifference to eating more, soon after starting a meal. This procedure is also one where the patient is exposed to the least risk of nutritional deficiencies.

2.      Gastric bypass, Roux en-Y (distal)

This variation of GBS works on reducing the absorption capacity of food, essentially starches and fats. It modifies and reduces the size of the small bowel to diminish its ability to absorb nutrients. The downside of this procedure is that the starches and fats which remain unabsorbed move through to the large intestine where they are exposed to bacterial actions which are liable to produce malodorous gases and irritants.

3.      Loop Gastric bypass or Mini-gastric bypass

This technique, which was first used in the mid-60s, has since been abandoned because of the side-effects and attendant risks involved. However it is used occasionally as an alternative to the Roux en-Y procedure because of its simplicity. In the mini-gastric bypass procedure the stomach pouch, which is kept long and narrow, is reconnected to the intestines roughly 6 feet from the stomach. The net effect is to bypass much of the intestine not connected to the pouch, and prevent food from entering it so reducing its nutrient absorbing capacity. Mini-surgeries are quicker to perform needing less recovery time. However patients are at risk of side effects like infections, pulmonary emboli, bleeding and death which is why they are rarely performed except under the most extreme circumstances.

Summary of Gastric Bypass Procedure

After GBS the volume of the stomach reduces by as much as 90 percent, very significantly reducing its functional capacity. The pouch that is constructed during surgery is usually created from that portion of the stomach which is most unlikely to stretch. Hence the reconstructed size, which is about 15 ml, is unlikely to stretch very much, though this does sometimes happen. By the time the pouch stretches, the desired weight loss has already been achieved. Compare this with a normal stomach which can sometimes stretch to as much as 1000 ml. A Diet After Bariatric Surgery should always be followed. Even if the pouch stretches, it can only hold a limited quantity of food, just adequate for maintenance of the new body weight.