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Gastric Bypass
A gastric bypass is a weight-loss operation that creates a small stomach pouch and reroutes the intestine, so you eat less and absorb fewer calories. It is highly effective for severe obesity.
Causes & risk factors
- Considered for severe obesity (usually BMI 40+, or 35+ with illness)
- When other weight-loss methods have not worked
- Very effective for improving or reversing type 2 diabetes
- Also helps severe reflux, sleep apnoea and joint problems
Common symptoms
- This is a procedure page, not a disease
- It treats severe obesity and related conditions
- Feeling full quickly and eating smaller meals afterwards
- Marked, sustained weight loss over the first year
Tests & diagnosis
- CBC
- HbA1c
- Vitamin B12 and iron
- LFT
- Endoscopy and heart/anaesthetic assessment before surgery
Treatment & management
- Keyhole surgery to make a small stomach pouch and reroute the bowel
- A staged diet from liquids to small solid meals
- Lifelong vitamin and mineral supplements (including B12 and iron)
- Regular follow-up and blood tests to prevent deficiencies
- Sustained healthy eating and activity for lasting results
When to see a doctor urgently
- Severe tummy pain, vomiting or fever after surgery — seek urgent care
- Sweating, dizziness or palpitations after sugary meals (dumping)
- Signs of anaemia or vitamin deficiency
- To discuss whether a bypass is right for you
Frequently asked questions
What is the difference between a sleeve and a bypass?
A sleeve removes part of the stomach so you eat less. A bypass makes a small pouch and reroutes the bowel, so you also absorb fewer calories. A bypass often helps diabetes and reflux more, but needs closer vitamin monitoring.
What is dumping syndrome?
After a bypass, sugary or fatty foods can pass quickly into the bowel, causing sweating, dizziness, cramps or diarrhoea. It is managed by eating slowly and avoiding high-sugar foods.
Explore more
Sources & further reading
- World Health Organization (WHO)
- MedlinePlus — U.S. National Library of Medicine
- Ministry of Health & Family Welfare, India
- Indian Council of Medical Research (ICMR)
Reviewed by Dr. Sanjay Anbu, MBBS. MedDroid is an AI medical assistant and can make mistakes. It provides general health information, not a diagnosis or medical advice — always consult a qualified clinician. In an emergency, contact your local emergency number immediately.