Effective, long-term weight loss and improved health — safely performed at Rattinan Clinic.

Gastric Bypass Surgery, also known as Roux-en-Y Gastric Bypass, is one of the most effective and well-established types of weight loss surgery. It works by reducing stomach size and altering the digestive pathway, helping patients lose weight and improve obesity-related health conditions.

At Rattinan Clinic in Bangkok, we offer gastric bypass as part of our advanced bariatric surgery program, with comprehensive pre- and post-operative care to help you achieve lasting results.

Gastric bypass is a bariatric procedure that involves two key steps:

1. Creating a small stomach pouch to limit food intake
   
2. Rerouting part of the small intestine to reduce calorie and nutrient absorption
   

This surgery also affects hunger hormones, often leading to reduced appetite or complete loss of hunger, and may decrease the likelihood of dumping syndrome (a condition where food moves too quickly into the intestine).

Laparoscopic (minimally invasive)
Small incisions are made in the abdomen, and the procedure is performed using a camera and fine surgical instruments. This technique reduces scarring, pain, and recovery time compared to open surgery.

Approximately 2–3 hours
The exact length depends on your anatomy and medical history. Our surgeons take every step to ensure precision and safety throughout the procedure.

1 to 2 nights
Most patients stay overnight for monitoring and initial recovery. You’ll be observed for pain management, hydration, and to ensure your digestive system is functioning properly before going home.

General anesthesia
You will be fully asleep and monitored by an anesthesiologist throughout the surgery to ensure comfort and safety.

2 to 3 weeks for most daily activities
Many patients return to light work or normal routines within this period.
However, full recovery—including adaptation to the new eating habits and physical activity—continues over several months with ongoing medical support.

This procedure may be recommended for individuals who:

• Have a BMI of 40 or more
  
• Have a BMI of 35 or more with obesity-related conditions (e.g. diabetes, hypertension)
  
• Suffer from GERD (acid reflux)
  
• Have not achieved weight loss through diet, exercise, or medication
  
• Are newly diagnosed with type 2 diabetes and not yet severely affected

Before undergoing gastric bypass at Rattinan Clinic, you will receive:

• Full medical evaluation (blood tests, imaging, physical exam)
  
• Psychological assessment (if necessary)
• Nutritional consultation and pre-surgery diet plan (low-calorie, high-protein) to reduce liver size and improve surgical outcomes

While gastric bypass is generally safe and highly effective, it may involve:

Short-Term Risks:

• Infection, bleeding
  
• Blood clots
  
• Anesthesia-related issues
  

Long-Term Risks:

• Nutritional deficiencies (vitamins and minerals)
  
• Dumping syndrome
  
• Gallstones
  
• Bowel obstruction (rare)
  

Patients must commit to regular follow-up and lifestyle changes to minimize risks.

To protect healing and support long-term success, patients follow a staged diet:

Broths, protein shakes, water

Soft-textured foods like blended vegetables, yogurt

Cooked vegetables, soft fruits, tender meats

Gradual reintroduction of a balanced, high-protein diet

Additional Tips:

• Eat slowly and chew thoroughly
  
• Avoid drinking fluids 30 minutes before/after meals
  
• Focus on protein, fiber, and portion control
  
• Avoid smoking and alcohol for better recovery and results

Lifelong supplements are required to prevent nutritional deficiencies:

• Multivitamins with iron, folic acid, and zinc
  
• Vitamin B12 (injection or oral)
  
• Calcium with Vitamin D
• Iron supplements (if prescribed)

• Begin with light walking after surgery
  
• Gradually increase activity with aerobic and strength exercises
  
• Commit to long-term lifestyle changes with the support of our care team

Post-operative care includes:

• Regular check-ups with our bariatric team
  
• Blood tests to monitor nutrient levels
  
• Ongoing weight tracking and nutritional support
  

Contact your doctor immediately if you experience:

• Persistent vomiting
  
• Severe abdominal pain
• Unusual fatigue or signs of deficiency

Patients typically achieve:

• 60–80% excess weight loss in the first 12–18 months
  
• Improvement or resolution of:
  
  • Type 2 diabetes
    
  • High blood pressure
    
  • Sleep apnea
    
  • Acid reflux
    
• Enhanced energy, mobility, and confidence
• A better quality of life with long-term support

Bariatric surgery is a procedure that reduces the size of the stomach to alter the digestive and nutrient absorption pathways in the small intestine. The primary goal is to help decrease food intake, reduce appetite, and control the absorption of calories into the body.

It is an option for individuals who are unable to lose weight through traditional methods such as dieting and exercise. Additionally, it helps reduce the risks associated with obesity-related conditions, such as diabetes and high blood pressure. Research has shown that bariatric surgery can provide continuous weight loss benefits and reduce the risk of obesity-related diseases.

In this article we’ll cover the types of procedures available, eligibility criteria, costs, and what to expect throughout the surgical journey.

Bariatric surgery refers to a set of medical procedures that reduce stomach size or alter the digestive process to promote weight loss. The primary goal is to limit food intake, reduce hunger, and control calorie absorption. These surgeries are particularly beneficial for individuals who have struggled with conventional weight-loss methods such as dieting and exercise.

• Significant weight loss – Helps patients lose and maintain a healthier weight.
• Health improvements – Reduces the risk of obesity-related diseases such as type 2 diabetes, heart disease, and high blood pressure.
• Better quality of life – Enhances mobility, boosts self-confidence, and improves mental well-being.

Bariatric surgery techniques generally fall into two categories:

• Restrictive procedures – Reduce stomach size, limiting food intake.
• Malabsorptive procedures – Alter the digestive tract, decreasing calorie absorption.

Bariatric surgery is suitable for individuals who meet specific criteria to ensure both safety and effectiveness. Candidates typically include:

• Individuals over the age of 18.
• Those with a Body Mass Index (BMI) of 27 or higher, particularly if they have obesity-related health conditions.
• Individuals who have attempted weight loss through diet, exercise, or other methods without success.

Those without medical contraindications for surgery.

People with a BMI of 40 or more are generally at high risk for obesity-related diseases, such as heart disease, type 2 diabetes, and hypertension. Bariatric surgery can help significantly reduce these risks by facilitating long-term weight management.

Those with a BMI in this range who suffer from conditions like type 2 diabetes, obstructive sleep apnea (OSA), or non-alcoholic fatty liver disease may benefit from bariatric surgery. The procedure can help manage and, in some cases, alleviate these conditions.

For those who have tried diet control, regular exercise, or weight loss medication without achieving significant or sustainable results, bariatric surgery may be a viable alternative. It is often considered a last-resort option when other weight-loss strategies have proven ineffective.

Candidates should fully understand the benefits, risks, and long-term lifestyle changes required after the procedure. Commitment to healthier eating habits, regular exercise, and ongoing medical follow-ups is essential for success.

Before undergoing bariatric surgery, patients must be evaluated by a qualified surgeon and healthcare team. This assessment ensures that they are suitable candidates and can handle the potential effects of the procedure.

Obesity is a condition in which excessive fat accumulation negatively impacts health, increasing the risk of serious diseases such as heart disease, type 2 diabetes, and hypertension. The Body Mass Index (BMI) is a commonly used tool for assessing obesity levels. It provides a standard measurement to determine whether an individual is underweight, at a healthy weight, overweight, or obese.

BMI is calculated by dividing a person’s weight in kilograms by the square of their height in meters. The formula is as follows:

BMI = Weight (kg) ÷ (Height (m) × Height (m))

Based on BMI values, individuals are classified into different weight categories:

• Below 18.5 – Underweight
• 18.5 – 24.9 – Normal weight
• 25 – 29.9 – Overweight
• 30 and above – Obese
• 40 and above – Severely obese

BMI provides a general guideline for weight assessment, but additional factors such as muscle mass and body composition should also be considered.

Waist circumference is another useful indicator, especially for assessing the risk of health conditions related to abdominal fat accumulation. Excess fat around the abdomen is strongly linked to metabolic disorders and cardiovascular diseases.

• Men: A waist circumference of more than 102 cm increases health risks.
• Women: A waist circumference of more than 88 cm indicates a higher risk of obesity-related conditions.

Measuring body fat percentage provides a more accurate understanding of fat distribution in the body. This can be assessed using specialized tools such as body fat analyzers or DEXA scans, which offer detailed insights into fat composition.

While BMI is a widely used metric, combining it with waist circumference and body fat percentage measurement allows for a more comprehensive evaluation of an individual’s overall health and risk factors associated with obesity.

Gastric sleeve surgery removes about 80% of the stomach, leaving a smaller, sleeve-shaped stomach. This significant reduction in stomach size helps to reduce appetite and allows patients to feel full after consuming smaller meals.

Success Rate: Patients typically experience a 60-70% reduction in excess weight within 1-2 years after surgery.

Gastric bypass surgery creates a small stomach pouch and reroutes a portion of the small intestine, which significantly reduces calorie absorption. This procedure is often recommended for patients with severe obesity and diabetes.

Who it’s best for:
Gastric bypass surgery is ideal for patients with severe obesity, particularly those with co-existing health issues like diabetes.

Mini gastric bypass is a simpler variation of the traditional gastric bypass. It involves creating a longer, single-loop bypass, which avoids the more complex rerouting of the intestines that is involved in the standard gastric bypass procedure.

Endoscopic sleeve gastroplasty is a non-surgical, minimally invasive procedure that uses an endoscope to stitch the stomach from the inside, reducing its size without the need for traditional surgery.

Recovery Time and Results
This procedure involves no external incisions, meaning there are no visible scars, and has a significantly shorter recovery time compared to traditional surgeries. However, it may not be as effective for individuals with extreme obesity, and the weight loss results can vary from patient to patient.

Revisional bariatric surgery is for patients who have already undergone a previous bariatric procedure but need further correction or modification. This may be necessary for patients who have not achieved their weight loss goals or who have experienced complications from their initial surgery.

Common Reasons for Revision:

• Inadequate weight loss
• Complications from the initial procedure
• Need for a more effective or tailored procedure to meet individual goals

These options provide various approaches to weight loss, depending on a patient’s specific needs, preferences, and health conditions.

As your trusted healthcare partner, our team of expert surgeons here at Rattinan Medical Center ensures the highest level of safety for all bariatric procedures. If you are considering weight loss surgery and unsure which method is best for you, we recommend consulting with our specialists to determine the most suitable and safe option tailored to your health needs.

The process begins with an initial consultation, which can be done virtually. During this consultation, patients will discuss their medical history, Body Mass Index (BMI), and determine their eligibility for bariatric surgery. Diagnostic tests, including blood work and imaging, may also be required to assess the patient’s overall health and suitability for the procedure.

Before the surgery, patients will need to follow specific instructions to ensure they are prepared. This may include adhering to a low-calorie diet to shrink the liver, which helps create better conditions for the surgery. Patients will also need to stop smoking and drinking alcohol at least four weeks before the procedure to promote better healing. Additionally, psychological and nutritional assessments may be conducted to help patients prepare for the lifestyle changes they will need to make after the surgery.

On the day of the surgery, patients will undergo the procedure under general anesthesia. The surgery typically takes between 1-3 hours, depending on the type of procedure being performed. Most patients will require a hospital stay of 1-3 days for monitoring and recovery before being discharged.

After the surgery, patients may experience mild discomfort, which can usually be managed with prescribed pain medications. Initially, patients will need to follow a liquid diet for the first two weeks before gradually transitioning to soft foods. Follow-up appointments, whether in-person or virtual, will be necessary to monitor the patient’s progress and ensure everything is healing properly.

To achieve lasting results, patients must commit to significant lifestyle changes. Healthy eating habits are essential, with a focus on prioritizing protein intake and avoiding sugary and high-fat foods. Regular exercise is also important to support weight loss and improve overall health.

Additionally, patients will need to take vitamin supplements to prevent nutrient deficiencies, a common issue after bariatric surgery. Joining support groups and attending counselling sessions can also be beneficial in helping patients adjust emotionally and mentally to the changes they are making in their lives.

Bariatric surgery has proven to be an effective pathway for significant, sustainable weight loss. However, as with any major surgical intervention, it’s important to understand that it comes with considerations that require careful thought and preparation.

The specific risks can vary based on the type of procedure—whether gastric bypass, sleeve gastrectomy, or another approach—as well as your individual health profile. We believe in empowering our patients with complete information so you can make the most informed decision for your health journey.

In the initial weeks following surgery, there are several factors we monitor closely:

Bleeding and Infection: As with any surgery, there’s a possibility of bleeding at the surgical site or infection at the incision points or internally.

Anastomotic or Staple Line Leaks: This occurs when digestive contents leak from where the stomach or intestine was joined. While uncommon, it requires immediate attention as it can lead to serious infection.

Blood Clots: Deep vein thrombosis (DVT) or pulmonary embolism (PE) are risks we take seriously. We implement preventive protocols to minimize this concern.

Respiratory Considerations: Some patients may experience temporary breathing difficulties or partial lung collapse, which we monitor and manage carefully.

Anesthesia Responses: Individual reactions to anesthesia can vary, and our anesthesia team is experienced in managing these situations.

Other Surgical Considerations: Rare complications can include temporary bowel obstruction or unintended contact with surrounding organs.

Beyond the initial recovery, there are ongoing factors that become part of your new health routine:

Nutritional Balance: This is perhaps the most significant long-term consideration. Because the surgery changes how your body absorbs nutrients, you’ll need lifelong supplementation, particularly:

• Vitamin B12, Iron (to prevent anemia)
• Calcium and Vitamin D (to maintain bone health)
• Folate and protein

Regular monitoring and supplementation become essential parts of your wellness routine.

Digestive Adjustments: Some patients, particularly after gastric bypass, may experience what’s called dumping syndrome—where certain foods, especially those high in sugar, move through your system more quickly, causing temporary discomfort. This typically becomes manageable as you learn which foods work best for your new system.

Gallstones: Rapid weight loss can increase the likelihood of gallstone formation, which we monitor through follow-up care.

Structural Changes: Over time, some patients may develop hernias at incision sites or experience narrowing at surgical connection points. These are manageable with proper monitoring.

Acid Reflux: Some procedures, particularly sleeve gastrectomy, may influence acid reflux patterns. We can work together to manage this if it occurs.

Weight Maintenance: Long-term success requires commitment to lifestyle changes. The surgery is a powerful tool, but sustained results depend on continued healthy eating patterns and activity levels.

Emotional Wellbeing: The journey involves both physical and emotional dimensions. Some patients may need support in adjusting to their new relationship with food and body image.

Follow-up Care: Occasional revision procedures may be needed to optimize your results or address any concerns that arise.

At Rattinan Clinic, we view bariatric surgery not as a single event, but as the beginning of a supported, long-term partnership. We believe that thorough education, realistic expectations, and comprehensive follow-up care are essential to your success.

We encourage you to have an in-depth conversation with our team about your individual health profile, specific risk factors, and the lifelong commitment to nutrition, supplementation, and regular monitoring that will become part of your wellness routine.

Every patient’s journey is unique, and we’re here to guide you with expertise, compassion, and the honest information you deserve.

Managing weight can be frustrating, especially when diets and exercise fail, and bariatric surgery costs in many countries seem out of reach.

What if you could achieve long-term weight loss with expert care at an affordable price?

At Rattinan Medical Center in Bangkok, gastric sleeve surgery reduces stomach size by 80%, helping control appetite and support lasting weight loss. 

With skilled surgeons, modern techniques, and comprehensive support for international patients, we offer world-class care at a fraction of the cost.

Frequently Asked Questions (FAQs)