Gastric Sleeve vs. Gastric Bypass

Below is a guide to understanding the differences between gastric sleeve and gastric bypass. The contrasts between these two surgeries are stark and can lead to common misunderstandings.

Gastric Bypass Surgery

Gastric Bypass is the most performed weight loss surgery in the United States. Considered the “gold standard” of bariatrics, gastric bypass is performed roughly 140,000 times in the United States alone.

Gastric Sleeve Surgery

Gastric Sleeve is a restrictive procedure that is quickly gaining notoriety among bariatric surgeons, because of its efficacy. Recent studies suggest that gastric sleeve works not only as a primer surgery but as a stand-alone surgery itself.

Gastric Sleeve vs. Gastric Bypass:

Gastric Sleeve

RNY Gastric Bypass



  • Reduces Stomach Size and Hunger Hormone Ghrelin
Restrictive & Malabsorptive

  • New Stomach Created (stoma)
  • Alters Digestion to Induce malabsoprtion
Stomach AlterationsStomach size reduced

  • 85% of the stomach is removed, leaving 3.5 oz capacity.
New Stomach is Created: Stoma.

  • Stomach is bypassed, with a new smaller stomach (stoma) created with intestines.
Changes to IntestineNo ChangeCut and Bypassed

  • Stoma is bypassed, then connected to the intestines. This induces malabsorption.
Operating Time
  • 1 to 3 hours
  • 2 hours
Average Hospital Stay
  • 2 to 3 days
  • 2 to 3 days
Time off Work
  • 2 weeks
  • 2 to 3 weeks
Recovery Time
  • 3 weeks
  • 3 months
  • Provides permanent weight loss.
  • Hunger urges reduced (Ghrelin hormone reduced)
    • High Expected Weight Loss
  • “Gold Standard” weight loss surgery, with many studies showing effectiveness.
  • Newer surgery with long-term results somewhat unknown
  • Stomach Could Enlarge
  • Significant lifetime changes to diet and eating.
  • Leakage, Bleeding, Vomiting all occur.
  • Daily Supplements and Vitamins Required.
  • Dumping Syndrome can occur.
Surgery Description
  • Stomach is cut, then sutured and stapled in a vertical shape. The 3.5 oz remaining stomach then induces patients who feel fuller faster and thus induce weight loss.
  • Stoma  (about 1/20-30cc) is connected to the small intestine. The small stomach induces smaller food capacity, the malabsorption induces calories to bypass without being absorbed.
  • Provides mild malabsorption of nutrients.
  • Patients can expect to lose 70% of excess weight.
Post Surgery Dietary Info:
  • Patient must eat 3 meals a day containing 600-800 calories per day (recommended for the first 24 months) and about 1000-1200 thereafter.
  • Patients must take vitamin and protein supplements to avoid deficiency (Multivitamin, Calcium, Vitamin B12, and Iron for menstruating women)
  • Patients must eat 3 small meals a day.
  • Patients must avoid sugar and fats to prevent Dumping Syndrome.
  • Patients must take vitamin and protein supplements to avoid deficiency (Multivitamin, Calcium, Vitamin B12, and Iron for menstruating women)
Scroll to top