Purpose:
Gastric bypass surgery is primarily performed to help a person lose excess weight and reduce the risk of developing life-threatening weight-related health problems, like:

• Heart disease
• Gastroesophageal reflux disease
• High cholesterol
• High blood pressure
• Diabetes
• Obstructive sleep apnea
• Cancer 
• Stroke
• Infertility 

Indications:
Gastric bypass surgery is generally performed in the following cases:

• When a person’s body mass index (BMI) is 40 or more
• When a person’s BMI is between 35 and 39.9 and the person has a weight-related health disorder
• When a person’s BMI is between 30 and 34 and the person has serious weight-related health disorders

Good candidate:
Gastric bypass surgery is usually recommended for the following candidates:

1. Body mass index (BMI), which is measured by dividing weight in kilograms by height in meter square) of 40 or more
2. BMI between 35 and 39.9, along with a weight-related health disorder
3. BMI between 30 and 34, along with serious weight-related health disorders

The following diagnostic tests may be performed before a gastric bypass surgery:

1. The doctor may recommend undergoing the following diagnostic tests before a gastric bypass surgery:
2. Physical examination: The doctor will evaluate the physical health of the patient. The symptoms and medical history of the patient will be noted.
3. Blood tests: Certain underlying medical conditions and the different blood parameters can be checked using these tests.
4. Urine analysis: It helps in the detection of certain types of infections.
5. Barium swallow test: The severity of acid reflux and the presence of abnormalities in the upper gastrointestinal tract can be detected using this test.
6. Ultrasound: Suspected gallstones or gallbladder inflammation can be detected by a gallbladder ultrasound.
7. Chest x-ray: The condition of the lungs and heart can be checked by the doctor using a chest x-ray.
8. Electrocardiogram (ECG): The electrical activity of the heart can be measured using this test.
9. Echocardiogram: A detailed image of the heart in motion can be obtained using this test.
   

Gastric bypass surgery can be done in different ways, which may include the following:

Roux-en-Y gastric bypass procedure: It is performed by cutting across the top portion of the stomach and then sealing it off from the rest of the stomach.
Biliopancreatic diversion with duodenal switch or extensive gastric bypass: It is performed by removing about 80% of the stomach leaving behind a tube-like pouch. The end part of the intestine is then connected to the duodenum, which is the first part of the small intestine. 
The doctor may perform the surgery using different techniques. The different techniques that can be used to perform gastric bypass surgery include:

1. Open surgery or the traditional method: 
This procedure is performed by the surgeon by making a large, open incision in the abdominal area. 
The top part of the stomach is then cut off and sealed from the rest of the stomach.
This results in the formation of a small pouch that can hold only a small quantity of food.
 
2. Laparoscopic surgery or minimally-invasive surgery:
This procedure involves the surgeon creating small incisions or cuts.
A tube with a camera on one end, known as a laparoscope, as well as other small surgical instruments are then inserted through these incisions to perform the procedure. 
This type of procedure has a more rapid recovery, lesser complications, and is less painful than open surgery.

3. Robotic-assisted surgery:
This is a type of laparoscopic surgery performed using robotic arms controlled by the surgeon by viewing the computer monitor attached to the laparoscopic camera.
Although this procedure is more expensive, it offers better precision and can maneuver hard-to-reach areas compared to the other techniques used.

The complications associated with gastric bypass surgery include:

• Bleeding
• Blood clot formation
• Infection
• Difficulty in breathing 
• Allergic reaction to the anesthetic agent
• Bowel obstruction 
• Gastrointestinal system leaks 
• Gallstones
• Hernia
• Malnutrition 
• Dumping syndrome that causes symptoms like nausea, vomiting, or diarrhea
• Hypoglycemia (low blood sugar)
• Stomach perforation 
• Vomiting
• Ulceration
• Death (rare)

1. You will most likely stay in the hospital for two to three days after the surgery.
2. It is normal to have some pain and discomfort after the procedure. You will be prescribed pain-relieving medications to relieve this pain.
3. Complete recovery following a gastric bypass surgery takes approximately three to four weeks.
4. You will need frequent follow-up appointments with your doctor for several months to monitor your health.

Home remedies:

The following home remedy tips will aid in a quick recovery following a gastric bypass surgery:

1. Take a liquid diet after surgery and gradually move to semi-solid and solid foods after a couple of weeks.
2. Take all your prescribed medications on time.
3. Take adequate rest after surgery.
4. Drink plenty of fluids throughout the day.
5. Keep your upper abdomen in an elevated position by using pillows or a recliner.
6. Avoid taking a bath for at least two days after the surgery.
7. Avoid strenuous exercises and heavy lifting for a couple of days after the surgery.

Benefits:

Gastric bypass surgery has the following advantages:

1. Long-term loss of weight
2. Treatment or reduction of different types of obesity-related diseases like high blood pressure, diabetes, and sleep apnea
3. Improved quality of life
4. Improved self-esteem and social life

Cost of gastric bypass surgery in India- 

The cost of gastric bypass surgery in Mumbai is between INR 3,50,000 to INR 6,00,000.
The cost of gastric bypass surgery in Delhi is between INR 3,25,000 to INR 5,50,000.
The cost of gastric bypass surgery in Bangalore is between INR 3,25,000 to INR 5,50,000.
The cost of gastric bypass surgery in Chennai is between INR 3,00,000 to INR 5,25,000.