Gastric Bypass
A surgical weight-loss procedure that reduces stomach size and reroutes the intestine, leading to significant and lasting weight loss.
Plain English
Patient-Friendly Explanation
Gastric bypass, also known as Roux-en-Y gastric bypass, is a surgical weight-loss procedure that creates a small stomach pouch and reroutes the small intestine. This reduces how much food you can eat and how many calories your body absorbs. It is one of the most effective and well-studied bariatric surgeries for people with severe obesity who have not achieved lasting weight loss through diet and exercise alone.
Medical
Clinical Definition
Roux-en-Y gastric bypass (RYGB) is a combined restrictive and malabsorptive bariatric procedure. The surgeon staples the upper stomach to create a 15–30 mL pouch and connects it directly to the mid-jejunum, bypassing the distal stomach, duodenum, and proximal jejunum. This reduces gastric capacity, alters gut hormone secretion (elevated GLP-1 and PYY, suppressed ghrelin), and induces micronutrient malabsorption. Typical excess weight loss is 60–80% at 1–2 years, with significant remission rates for type 2 diabetes, hypertension, and obstructive sleep apnoea.
Key Insight
Why It Matters
While gastric bypass is not performed at Accord Medical itself, Dr Joseph Wang helps patients understand all available weight-loss options — including surgical referrals — as part of a comprehensive weight management plan. Understanding the procedure helps patients make informed decisions about their long-term health.
Sources
Reviewed against standard medical references.
Medically reviewed by
Family Physician & Registered Acupuncturist, Accord Medical Clinic. MBBS (NUS), Graduate Diploma in Family Medicine (NUS), Graduate Diploma in Acupuncture (Singapore College of TCM).
Last reviewed: August 2026
This page is general health education, not medical advice. Whether any treatment is appropriate for you is a decision made in consultation after assessment.
