Gastric Bypass


Gastric bypass surgery is primarily based on the direct diversion of food to the last segment of the small intestines without running through the stomach and a great portion of the small intestines. Obesity is characterized with highest increase in prevalence around the world. Even though there are tens of medical etiologies of obesity, the most important ones are abnormal weight gain and sedentary lifestyle. Life time of obese patients is approximately 15 years shorter than other people due to diseases caused by obesity, including but not limited to hypertension, type 2 diabetes, hyperlipidemia, ischemic heart disease etc. Obesity is a risk factor for cancers such as colorectal cancers, breast cancer and prostate cancer.
There are various types of gastric bypass surgery: these are Roux-en-Y gastric bypass and biliopancreatic diversion with duodenal switch.

These methods aim bypassing foods directly to duodenum or initial segments of small intestine with no or minimal contact of foods to stomach by removing a part of stomach or without need to remove a part of stomach. Recently, those surgeries can be performed with laparoscopic methods. Comparing to sleeve gastrectomy, surgery-related complications are more commonly accompanied by long-term postoperative metabolic problems in all of these methods. More weight loss is achieved and can be maintained up to 2 years. While they require more vitamin supplements, they bring about problems, such as chronic diarrhea, bad breath etc.

Why is this procedure done?

The surgeries that are carried for weight loss are called bariatric surgery. Common purpose of them is to reduce the excess weight and thus prevent life threatening complications caused by obesity, such as heart diseases, high blood pressure, sleep apnea, diabetes mellitus etc.

There are some criteria for gastric bypass surgery to be performed. First of all, the patient should fail optimal or target body weight despite diet and exercise. Just as the case for all health issues, surgery should be considered as the last option. The commonly accepted two criteria are high BMI (>40) or lower BMI (35-39) accompanied by coexisting obesity-induced serious health conditions. Therefore, it will be the most suitable approach for you to ask all your questions to your surgeon before deciding on a gastric bypass surgery to manage the post operative period.


As the case for all surgeries, gastric bypass surgery involves some risks.Although all possible measures that modern medicine allows are taken to prevent occurrence of risks, it is no means possible to warrant that the risks will be completely eliminated.

•    Bleeding
•    Infection
•    Thrombosis (blood clot)
•    Leakage from anostomosis line
•    Damage to other organs
•    Transition to open surgery
•    Anesthesia-related complications
•    Abdominal wall hernia
•    Nutritional disorder
•    Gastric perforations, ulcer, erosion
•    Obstruction of the digestive tract
Your surgeon will explain in detail whether those risks apply to you or if so, the rate of occurrence.


The first phase of preoperative preparation is same in all Medicana Hospitals. Decision of gastric bypass surgery is made following a series of medical tests and examinations. Your doctor will make a comprehensive assessment to determine whether this surgery helps your complaints or not or whether you are healthy enough to undergo this surgery.In the preoperative period, all of your prescription and over-the-counter medications, your comorbidities such as obesity-induced hypertension, diabetes mellitus and cardiovascular diseases, and your overall health will be assessed. All these assessments will both help you be ready for the surgery and minimize the problems that can be encountered during or after the surgery.

•    Review of health history
•    A detailed physical examination
•    Necessary laboratory tests and radiology studies
•    Assessment by anesthesiologist and other laboratory tests and radiology studies to minimize anesthesia-related complications

After it is verified that the surgery does not pose risk, you will be asked to quit smoking, if you are a smoker, and to stop taking certain medications that increase risk of bleeding. All other prescribed and over-the-counter medications, herbal products and supplements will also be questioned and you will be informed to continue or stop taking them.
A preoperative discussion with your surgeon about gastric bypass surgery is very important. All details of the procedure, potential risks and healing period are explained. Moreover, it is reasonable to plan discharge, post-discharge accommodation and travel at this phase in order to manage postoperative period better.

Surgery and early postoperative period

Gastric bypass surgery is performed under general anesthesia. Typically, laparoscopy is used for this surgery. However, conventional open surgery can be performed if you previously had an abdominal surgery or due to some reasons determined and informed to you by your surgeon.

Your surgeon makes small incisions. First, your abdominal cavity is inflated by CO2 gas through one of those incisions. Then, a camera is inserted into your abdominal cavity. Other incisions are used for surgical instruments to be inserted into your abdominal cavity.
There are two types of bypass surgery.


It is the most common type of gastric bypass surgery. At most 10 % portion of the uppermost segment of the stomach is left and the remaining part is closed. The new small stomach is connected to the last segment of the small intestines. Thus, 90 % of the stomach and the first segment of the small intestines are bypassed.

Biliopancreatic diversion with duodenal switch:

Since duodenal switch directly affects the metabolism, it leads to more weight loss. It is a good method especially for people whose BMI is above 55kg/m2. This surgery not only limits food intake, but it also reduces absorption of foods. It is an efficient therapeutic method for diabetes, hypertension and high cholesterol caused by excessive weight. It is beneficial for patients who consume foods rich in fat as it decreases fat absorption. Although it is one of the obesity surgery methods that ensure the maximum weight loss, it is not a common one due to many peroperative and postoperative complications. Malodorous chronic diarrhea and vitamin and protein deficiencies secondary to decreased fat absorption are common after this surgery.

After you recover from anesthesia and you are ready to walk, you will be mobilized by or under supervision of our healthcare professionals.You will be given pain killer(s) after the surgery in order to manage the postoperative pain.

Treatments will be started and measures will be taken to eliminate risks arising out of clot formation.You may also need to use antibiotics to prevent a possible infection.It is very important that you follow all instructions of your doctor after the surgery to protect and support the outcome of the surgery.

You should see your surgeon for follow-up visits that are scheduled before you are discharged.If you experience warmth and redness in your incision line, or if you have a fever or any symptoms that you think are due to surgery after you are discharged, contact your surgeon immediately.


A very different life, in many aspects, is waiting for you after gastric bypass surgery. Primarily, you need to follow the instructions of your physician and your dietitian to the letter.
Patients are required to follow some dietary restrictions in early post operative period after bariatric surgeries. They are allowed to eat only liquid foods at first, and next, soft foods are gradually allowed followed by a routine diet that should be complied for the rest of the life.

Both digestive system is restricted and absorption is affected in gastric bypass surgery. Due to restrictions in absorption of nutrients, you will necessarily attend routine follow-up visits, provided more frequently in the first several months. Additionally, you should also take some vitamin and mineral supplements recommended by your physician. For you to lead a healthy life, your weight loss process is also required to be managed carefully.

Your body should be adapted to weight loss process and accordingly, you should immediately seek medical help from your surgeon or from a healthcare facility, if you feel any abnormality in your overall health while you lose weight.You should keep in mind that you will not be able to lose weight or you will regain weight unless you do not comply with dietary and life style change recommendations of your physician, your dietitian and other healthcare providers.

Created at 11.10.2023 03:42
Updated at 28.10.2023 11:53


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