by Mahnke D
Laparoscopic mini-gastric bypass, sleeve gastric bypass


A mini gastric bypass is a procedure done on the stomach and intestines to help people lose weight. It is a type of bariatric surgery.

Abdominal Organs
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Reasons for Procedure

A mini-gastric bypass is a treatment for obesity . The procedure will help limit overeating and decrease how many calories you absorb.

A mini gastric bypass may be recommended for people with a:

  • Body mass index (BMI) greater than 40
  • BMI greater than 35 with cardiovascular disease, sleep apnea , or uncontrolled type 2 diabetes
  • BMI greater than 35 with severe physical limitations that affect employment, mobility, and family life

This procedure may be done after a person has failed to lose weight through other methods such as healthful eating and exercise.

Benefits of bariatric surgery will depend on lifestyle changes that are also adopted. Benefits may include:

  • Long-term weight loss
  • Improvement in many obesity-related conditions, such as diabetes, sleep apnea, high blood pressure , and high cholesterol
  • Improved mobility and increased energy
  • Improved mood, self-esteem, and quality of life
  • Reduced risk of dying from cardiovascular disease

Possible Complications

Problems from the procedure are rare, but all procedures have some risk. Your doctor will review potential problems, like:

  • Adverse reaction to anesthesia, especially in patients who also have sleep apnea
  • Infection
  • Blood clot formation in the veins of the legs or lungs
  • Excess bleeding
  • Leaking of stomach contents into the abdominal cavity
  • Hernia formation
  • Death (rare)

Conditions that may develop after surgery may include:

  • Gallstones
  • Indigestion or ulcers
  • Scar tissue formation creating a bowel obstruction
  • Low blood sugar— hypoglycemia
  • Nutritional deficiencies particularly low levels of protein or vitamins
  • Body image distortion—patients have difficulty adjusting to their new appearance
  • Inability to lose weight after surgery
  • Excess weight loss (rare)

Problems are more common in older adults. Factors that may increase the risk of problems include:

  • Smoking
  • Recent or chronic illness such as kidney disease
  • Diabetes
  • Heart or lung disease
  • Bleeding or clotting disorders

Talk to your doctor about these risks before the procedure.

What to Expect

Prior to Procedure

Each bariatric surgery program has specific requirements. Your program will likely include:

  • A physical exam and review of your medical history
  • Attempts to lose weight through medically approved dietary means
  • Ongoing consultations with a registered dietician
  • Mental health evaluation and counseling

Before your procedure:

  • Talk to your doctor about your medications, herbs, and dietary supplements. You may be asked to stop taking some medications up to one week before the procedure.
  • Do not start taking any new medications, herbs, or supplements without talking to your doctor.
  • Arrange for a ride to and from the hospital.
  • Arrange for help at home as you recover.
  • You may be asked to take laxatives or give yourself an enema to clear your intestines.
  • The night before your surgery, eat a light meal. Do not eat or drink anything after midnight unless told otherwise by your doctor.
  • Shower or bathe the morning of your surgery.


General anesthesia will be used to. You will be asleep during the surgery.

Description of the Procedure

An IV line will be placed in your arm. Fluids and medication will be delivered through this line during the procedure. A breathing tube will be placed through your mouth and into your throat. It will help you breathe during surgery.

Small incisions will be made in the abdominal wall. A camera and surgical instruments will be passed through these incisions. The stomach will be divided into 2 parts. One part will be reconstructed to resemble a tube. The first part of the small intestine will then be bypassed by connecting the stomach tube to a section of the small intestine further down than previous attachment point.

The small incisions will be closed. Bandages may be placed over the incision sites.

Immediately After Procedure

After the operation, you will be taken to the recovery room for observation.

How Long Will it Take?

About 1 ½ to 2 ½ hours

How Much Will it Hurt?

Anesthesia prevents pain during surgery. As you recover, you may have some pain. You will be given pain medication.

Eating too much will cause discomfort. Work with a dietitian to create a meal plan that will provide enough nutrition without causing discomfort.

Average Hospital Stay

This is done in a hospital. The usual length of stay is 2 days. If you have any problems, you may need to stay longer.

Post-procedure Care

At the Hospital

While you are recovering at the hospital, you may receive the following care:

While you are recovering at the hospital, you may receive the following care:

  • Pain medication will be given as needed.
  • On the day after surgery—you will have x-rays to check for leaks from the stomach.

Your stomach will not only be smaller, but will also be swollen after surgery. This will limit the types and amount of food you can eat. You will be started on liquids only. Medications or vitamins may also need to be crushed up or taken as liquid.

While in the hospital, you may be asked to do the following:

  • Use an incentive spirometer to help you take deep breaths. This helps prevent lung problems.
  • Wear elastic surgical stockings or boots to promote blood flow in your legs.
  • Get up and walk in the hall daily.
At Home

For best success, you will need to practice lifelong healthy eating and exercising habits. Walk as soon as possible. Make a goal to exercise daily.

You will meet regularly with your healthcare team for monitoring and support.

You may have emotional ups and downs after this surgery. Ask your doctor about support groups or counseling that may help.

Your new stomach is small and slow to empty, causing you to feel full quickly. Therefore, you need to eat very small amounts and eat every slowly. Some basic steps may include:

  • You will begin with 4-6 meals per day. A meal is 2 ounces of food. For the first 4-6 weeks after surgery, all food must be pureed.
  • After you move to solid foods, you will need to consume enough protein. Follow your dietitian’s meal plans.
  • Avoid sweets and fatty foods.
  • Eating too much or too quickly can cause vomiting or intense pain under your breastbone. Most people quickly learn how much food they can eat.
  • If you are taking medications or supplements:
    • Crush any non-chewable pills
    • Opt for chewable pills or liquid when possible

Call Your Doctor

Call your doctor if any of these occur:

  • Signs of infection, including fever and chills
  • Redness, swelling, increasing pain, excessive bleeding, or discharge from the incision site
  • Cough, shortness of breath, chest pain, or severe nausea or vomiting
  • Worsening abdominal pain
  • Blood in the stool
  • Pain, burning, urgency or frequency of urination, or persistent bleeding in the urine
  • Pain or swelling in your feet, calves, or legs
  • Sudden shortness of breath or chest pain
  • New or unexpected symptoms

If you think you have an emergency, call for emergency medical services right away.


American College of Gastroenterology 

American Society for Metabolic and Bariatric Surgery 


Canadian Association of Gastroenterology 

Weight Loss Surgery 


Bariatric surgery. EBSCO DynaMed Plus website. Available at:  . Updated October 23, 2017. Accessed January 10, 2018.

Bariatric surgery. National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: Accessed January 10, 2018.

Maciejewski ML, Livingston EH, Smith VA, et al. Survival among high-risk patients after bariatric surgery. JAMA. 2011;305(23):2419-2426.

Obesity surgery: Weight loss surgery. Cleveland Clinic website. Available at: Accessed January 15, 2013.

Weight loss surgery (bariatric surgery). Boston Medical Center website. Available at: Accessed January 10, 2018.

Your bariatric surgery experience. Allegheny Health Network website. Available at: Accessed January 10, 2018.

Revision Information

  • Reviewer: EBSCO Medical Review Board Daus Mahnke, MD
  • Review Date: 11/2018
  • Update Date: 12/20/2014