What Are The Different Types, Procedures And Risks Of Bariatric Surgery?

By Dr. Deep Goel in Surgical Gastroenterology, Advance Laparoscopic & Bariatric Surgery

Dec 07 , 2023 | 15 min read

Bariatric surgery, also known as weight loss surgery, is a medical procedure designed to help individuals with severe obesity achieve significant and sustainable weight loss. It involves surgically modifying the gastrointestinal tract to restrict food intake or alter the absorption of nutrients, resulting in reduced hunger and increased feelings of fullness. Bariatric surgery is considered a major undertaking and requires comprehensive preoperative evaluation, postoperative care and long-term lifestyle changes to ensure successful outcomes.

Types of Bariatric Surgery

There are several types of bariatric surgery, each with its technical approach and mechanism of weight loss. One common procedure is gastric bypass, where a small pouch is created at the top of the stomach and connected directly to the small intestine, bypassing a portion of the stomach and upper intestine.

Gastric sleeve surgery involves removing a large portion of the stomach to create a smaller, sleeve-shaped stomach. Adjustable gastric banding is where a band is placed around the upper part of the stomach, creating a small pouch that can be adjusted over time to control food intake. Biliopancreatic diversion with duodenal switch is a more complex surgery involving a partial gastrectomy, intestinal bypass, and rerouting of digestive juices.

Gastric Sleeve

Gastric sleeve surgery, also known as sleeve gastrectomy, is a type of bariatric surgery that involves the removal of a large portion of the stomach to create a smaller, sleeve-shaped stomach. This procedure is performed laparoscopically, using small incisions and a camera-guided surgical tool. By reducing the size of the stomach, gastric sleeve surgery restricts the amount of food that can be consumed, leading to weight loss. Gastric sleeve surgery is less complex than some other bariatric procedures and has shown to be effective in achieving significant and sustained weight loss.

Roux-En-Y (Roo-En-Wy) Gastric Bypass

Roux-en-Y gastric bypass surgery is a type of bariatric surgery that combines both restriction and malabsorption techniques to achieve weight loss. During this procedure, a small pouch is created at the top of the stomach by stapling a section of it. This restricts the amount of food that can be consumed. The small intestine is then divided, and the lower portion is connected to the newly created pouch, bypassing the rest of the stomach and upper intestine. This reduces the absorption of calories and nutrients.

The upper portion of the small intestine is reattached further down, allowing digestive juices to mix with food. Roux-en-Y gastric bypass surgery leads to significant weight loss by restricting food intake and altering the absorption of nutrients, while also influencing hunger and satiety hormones. This bariatric laparoscopic surgery results in smaller incisions and quicker recovery compared to open surgery. 

Biliopancreatic Diversion With Duodenal Switch (Bpd-Ds)

BPD-DS is a complex type of bariatric surgery that combines both restrictive and malabsorptive techniques to achieve weight loss. 

A large portion of the stomach is removed, creating a smaller stomach pouch similar to a sleeve gastrectomy. The small intestine is then rearranged, diverting the food from the stomach pouch to a lower section of the small intestine, bypassing a significant portion of the intestines. This reduces the absorption of calories and nutrients.

The BPD-DS procedure is more extensive than other bariatric surgeries, but it offers the most significant and sustained weight loss results.

Stomach Intestinal Pylorus Sparing Surgery (Sips)

SIPS, also known as single anastomosis duodenal-ileal bypass with sleeve gastrectomy (SADI-S), is a relatively new type of bariatric surgery that combines elements of sleeve gastrectomy and intestinal bypass. A portion of the stomach is removed to create a smaller sleeve-shaped stomach. However, unlike traditional gastric bypass surgery, SIPS involves a single connection between the remaining stomach and the small intestine, bypassing a larger portion of the small intestine. SIPS is designed to achieve significant weight loss while preserving the pylorus, the valve between the stomach and small intestine, which may help reduce the risk of complications such as dumping syndrome. Long-term studies are still needed to fully evaluate its effectiveness and safety compared to other bariatric surgeries.

Vertical Banded Gastroplasty (Vbg)

VBG, also known as stomach stapling, is a restrictive bariatric surgery technique designed to limit food intake and promote weight loss. A small upper pouch is created by stapling the stomach vertically, dividing it into two sections. The pouch restricts the amount of food that can be consumed, promoting a feeling of fullness with smaller portions. To prevent the pouch from stretching, a band is typically placed around it. The band serves as a physical restriction to control food passage and increase satiety.

VBG aims to limit food intake while preserving normal digestion and nutrient absorption. However, compared to other bariatric procedures, VBG has shown a higher risk of complications, such as band erosion and dilation of the stoma. Due to these risks and advancements in other techniques, VBG is now less commonly performed and has been largely replaced by more effective and safer bariatric surgeries.

Bariatric Surgery Conditions

Bariatric surgery is typically recommended for individuals who meet certain conditions and criteria. The primary condition is severe obesity, typically defined as having a body mass index (BMI) of 40 or higher. However, individuals with a BMI of 35 or higher and obesity-related health conditions, such as type 2 diabetes, hypertension, or sleep apnea, may also be considered candidates for bariatric surgery. Other factors that are taken into account include previous unsuccessful attempts at weight loss through non-surgical methods, overall physical and mental health, and the ability to commit to the necessary lifestyle changes post-surgery. Patients need to undergo comprehensive evaluation and consultation with a medical professional to determine their eligibility and suitability for bariatric surgery.

High Cholesterol

High cholesterol, known as hypercholesterolemia, is a condition characterised by an elevated level of cholesterol in the blood. Cholesterol is a waxy substance produced by the liver and obtained through diet, and it is essential for various bodily functions. However, high levels of cholesterol, particularly low-density lipoprotein (LDL) cholesterol, commonly referred to as "bad" cholesterol, can increase the risk of cardiovascular diseases such as heart attack and stroke. Factors contributing to high cholesterol include an unhealthy diet, a sedentary lifestyle, obesity, and genetic predisposition.

High Blood Pressure

High blood pressure, also known as hypertension, is a common medical condition in which the force of blood against the artery walls is consistently too high. It is often referred to as the "silent killer" because it usually does not cause noticeable symptoms but can lead to serious health problems if left uncontrolled. Risk factors for high blood pressure include obesity, sedentary lifestyle, unhealthy diet, smoking, family history, and age. If left untreated, high blood pressure can damage blood vessels, leading to heart disease, stroke, kidney problems, and other complications.

High Blood Sugar

High blood sugar, known as hyperglycaemia, occurs when there is an excessive level of glucose (sugar) in the bloodstream. It is commonly associated with diabetes mellitus, a chronic metabolic disorder. When the body cannot effectively regulate blood sugar levels, it can lead to various complications. Factors contributing to high blood sugar include a diet high in refined carbohydrates, a sedentary lifestyle, obesity, stress, and certain medical conditions. Symptoms of high blood sugar include frequent urination, excessive thirst, fatigue, blurred vision, and slow wound healing. Long-term uncontrolled hyperglycaemia can damage organs, nerves, and blood vessels. 

Type 2 Diabetes

Type 2 diabetes is a chronic metabolic disorder characterised by high blood sugar levels due to insulin resistance and insufficient insulin production. It is the most common form of diabetes, typically developing in adulthood, although it can occur in younger individuals as well. Risk factors include obesity, sedentary lifestyle, family history, age and certain ethnic backgrounds. Symptoms may include increased thirst, frequent urination, fatigue, blurred vision and slow wound healing. Type 2 diabetes can lead to various complications such as cardiovascular disease, kidney damage, nerve damage and eye problems.

Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a sleep disorder characterised by a repetitive partial or complete blockage of the upper airway during sleep, leading to interruptions in breathing. It occurs when the muscles in the throat relax, causing the airway to narrow or close off. Symptoms of OSA include loud snoring, gasping or choking during sleep, daytime sleepiness, morning headaches and difficulty concentrating. OSA can have significant health consequences, such as an increased risk of cardiovascular disease, high blood pressure, stroke and diabetes.

Heart Disease

Heart disease, also known as cardiovascular disease, refers to a range of conditions that affect the heart and blood vessels. It encompasses various conditions such as coronary artery disease, heart failure, arrhythmias and valvular heart disease. Risk factors for heart disease include high blood pressure, high cholesterol levels, smoking, obesity, diabetes, family history and an unhealthy lifestyle. Symptoms may vary depending on the specific condition but can include chest pain, shortness of breath, fatigue, palpitations and swelling in the legs. Heart disease can lead to serious complications such as heart attacks, strokes and heart failure, which can significantly impact the quality of life and be life-threatening. 

Bariatric Surgery Procedures

Bariatric surgery procedures are surgical interventions aimed at helping individuals with severe obesity achieve significant weight loss. These procedures work by restricting the amount of food intake, altering digestion or both. Some common bariatric surgery procedures include:

  • Gastric Bypass: Gastric bypass surgery procedure involves creating a small stomach pouch and rerouting the intestines to bypass a portion of the stomach and upper intestine. It restricts food intake and reduces calorie absorption.

  • Gastric Sleeve Surgery: In Gastric sleeve surgery procedure, a large portion of the stomach is surgically removed, leaving behind a smaller, sleeve-shaped stomach. It restricts food intake and decreases appetite.

  • Adjustable Gastric Banding: A band is placed around the upper part of the stomach, creating a small pouch. The band can be adjusted to control food intake, restricting the amount of food consumed.

  • Biliopancreatic Diversion With Duodenal Switch: This procedure combines a partial gastrectomy, removing a portion of the stomach, with intestinal bypass. It restricts food intake and reduces nutrient absorption.

Risks Associated With Bariatric Surgery

Bariatric surgery, like any surgical procedure, carries certain risks and potential complications. Some common risks associated with bariatric surgery include infection, bleeding, blood clots, adverse reactions to anaesthesia and leaks or blockages in the digestive system. There is also a risk of developing nutritional deficiencies, as the procedures may affect the body's ability to absorb certain nutrients. In addition, some patients may experience complications specific to the type of bariatric surgery they undergo, such as dumping syndrome, gallstones or maladaptive eating behaviours.

  • Bleeding - Bleeding is a potential complication of bariatric surgery. During the surgical procedure, blood vessels may be cut or disrupted, leading to bleeding. In some cases, bleeding may occur immediately after the surgery, while in others, it may develop days or weeks later. Excessive bleeding can result in complications such as anaemia, blood transfusions, or the need for additional surgical interventions to control the bleeding. Symptoms of bleeding may include persistent or worsening abdominal pain, lightheadedness, weakness, or signs of internal bleeding.
  • Infection - Infection is a potential complication following bariatric surgery. Surgical procedures create openings in the body, increasing the risk of bacterial or fungal infections. Infection can occur at the incision site or in deeper tissues, such as the surgical site or internal organs. Symptoms of infection may include redness, swelling, warmth, pain, fever or drainage from the incision site. In severe cases, infections can spread throughout the body and lead to sepsis, a life-threatening condition. Preventive measures, such as antibiotic prophylaxis, sterile surgical techniques and proper wound care, are taken to minimise the risk of infection.
  • Blood Clots - Blood clots, also known as deep vein thrombosis (DVT) or pulmonary embolism (PE), are potential complications of bariatric surgery. The surgical procedure, prolonged immobility during recovery, and changes in blood flow can increase the risk of blood clot formation. A blood clot can form in the legs and potentially travel to the lungs, causing a life-threatening pulmonary embolism. Symptoms may include leg pain, swelling, warmth, shortness of breath, chest pain, or coughing up blood.
  • Hernias - Hernia occurs when an internal organ or fatty tissue protrudes through a weakened area or opening in the abdominal wall. Bariatric surgery, particularly procedures that involve incisions in the abdomen, can increase the risk of hernias. Symptoms may include a visible bulge, pain, discomfort or a feeling of heaviness in the abdomen or groin area. Hernias require surgical repair to prevent complications such as bowel obstruction or strangulation.
  • Small Bowel Obstruction - Small bowel obstruction occurs when there is a blockage in the small intestine, preventing the normal passage of food and digestive fluids. Bariatric surgery can increase the risk of small bowel obstruction due to factors such as adhesions, internal hernias or strictures. Symptoms may include severe abdominal pain, nausea, vomiting, bloating and the inability to pass gas or have a bowel movement. Prompt medical attention is necessary as untreated small bowel obstruction can lead to bowel tissue damage or perforation. Treatment typically involves surgery to remove the blockage and repair any underlying causes.
  • Acid Reflux - Acid reflux, also known as gastroesophageal reflux disease (GERD), can be a complication of bariatric surgery. Certain procedures, such as gastric sleeve surgery, can potentially increase the risk of acid reflux symptoms. This occurs when stomach acid flows back into the oesophagus, causing heartburn, regurgitation, chest pain or difficulty swallowing. Acid reflux can be caused by alterations in the anatomy or function of the stomach and oesophagus after surgery.
  • Anaesthesia-Related Risks - Anaesthesia is necessary to ensure a pain-free surgical procedure, but it carries inherent risks. These risks can include adverse reactions to medications, respiratory problems, cardiovascular complications, allergic reactions, and complications related to intubation. Patients with obesity may have specific challenges during anaesthesia, such as difficulty in airway management and an increased risk of complications due to underlying health conditions. Anesthesiologists and surgical teams take precautions, including thorough preoperative evaluation and monitoring during the surgery, to minimise these risks.
  • Chronic Nausea And Vomiting - Chronic nausea may occur due to various reasons, including changes in stomach size, altered digestion or issues with food tolerance. Nausea and vomiting can significantly impact a patient's quality of life and nutritional status. It is important to identify the underlying cause, which could range from dietary issues to anatomical complications, such as strictures or stenosis.
  • Dilation Of Oesophagus - Dilation of the oesophagus, also known as oesophagal dilation, occurs when the oesophagus becomes stretched or widened, leading to difficulties in swallowing and potential food blockages. It can be caused by various factors, such as strictures, scar tissue formation or changes in anatomy after surgery. Oesophageal dilation may require endoscopic procedures to widen or remove blockages in the oesophagus.
  • Inability To Eat Certain Foods - After bariatric surgery, patients may experience difficulty or an inability to eat certain foods. This is primarily due to changes in the digestive system, such as reduced stomach size or alterations in the digestive process. Some foods that are high in fat, sugar or fibre may be poorly tolerated and can lead to discomfort, nausea, vomiting or diarrhoea. The focus post-surgery shifts towards consuming nutrient-dense, protein-rich foods while limiting processed, high-calorie, or hard-to-digest items. Patients are typically advised to follow a specific dietary plan, which may include smaller portion sizes, chewing food thoroughly, avoiding carbonated beverages, and gradually reintroducing foods.
  • Obstruction of Stomach - Obstruction of the stomach can occur when there is a blockage or narrowing in the stomach, preventing the normal flow of food. This obstruction can be caused by various factors, including scar tissue formation, adhesions, or anatomical changes resulting from the surgery. Symptoms may include severe abdominal pain, nausea, vomiting, bloating, and the inability to eat or drink. Prompt medical attention is crucial if a stomach obstruction is suspected, as it can lead to serious complications such as dehydration, malnutrition, or bowel perforation.
  • Weight Gain Or Failure To Lose Weight - Weight gain or the inability to lose weight after bariatric surgery can be a frustrating complication. While bariatric surgery is highly effective in promoting weight loss, certain factors can contribute to weight regain. These may include poor adherence to dietary guidelines, overeating, lack of physical activity, psychological factors, hormonal imbalances or the body's natural tendency to regain weight. Additionally, the surgery's long-term effects on metabolism and weight regulation may vary among individuals. Addressing these challenges often requires a comprehensive approach that includes nutritional counselling, behaviour modification, support groups, regular exercise and close follow-up with healthcare professionals. 


Bariatric surgery has emerged as a life-changing solution for individuals struggling with severe obesity. It offers significant and sustained weight loss, along with various health benefits and improvements in quality of life. Different types of bariatric surgery procedures provide options tailored to individual needs and goals. However, it is crucial to understand the potential risks and complications associated with these procedures and to make informed decisions with the guidance of healthcare professionals. Bariatric surgery is not a standalone solution but a tool that requires a long-term commitment to lifestyle changes, including dietary modifications, regular exercise and ongoing support. With proper post-operative care and adherence to recommended guidelines, bariatric surgery can be a transformative journey towards improved health and well-being.

Frequently Asked Questions

1. How long does the recovery process typically take after Bariatric Surgery?

The recovery process after bariatric surgery typically takes about 4-6 weeks, during which patients gradually resume normal activities while following post-operative guidelines for diet and exercise.

2. Will i need to make significant changes to my diet and lifestyle after the Bariatric Surgery?

Yes, significant changes to your diet and lifestyle are necessary after bariatric surgery. This includes following a specific diet plan, portion control, regular exercise, and ongoing support for long-term success.

3. How soon can i expect to see weight loss results after undergoing Bariatric Surgery? 

Weight loss results can vary among individuals, but many patients start to see significant weight loss within the first few months after bariatric surgery, with continued progress over the following year or more.

4. Can bariatric surgery be reversed if needed? 

While bariatric surgery is typically considered irreversible, some procedures can be partially reversed or revised in certain circumstances. Reversal or revision is a complex decision and should be discussed with your healthcare team to evaluate the potential risks and benefits.

5. Are there any age restrictions for Bariatric Surgery?

There is no strict age restriction for bariatric surgery, but eligibility is typically determined on a case-by-case basis. Factors such as overall health, body mass index (BMI) and the ability to withstand surgery and recovery are considered during the evaluation process.