Gastric Sleeve Surgery: What to Expect on the Day of Surgery

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Gastric sleeve surgery, also known as “sleeve gastrectomy,” is a procedure in which a major portion of the stomach is removed to promote rapid weight loss. The procedure is typically performed in a hospital under general anesthesia and the surgery usually takes between 40 and 70 minutes.

If you’re thinking about gastric sleeve surgery, it’s always a good idea to understand what happens on the day of the procedure. It can be helpful to know the timeline of what you may experience immediately before, during, and after surgery.

Operation room surgery
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Before the Surgery

As is the case with all major surgeries, before gastric sleeve surgery starts, healthcare providers have to make sure your body is ready. In the pre-operative room, you’ll have a final consultation and evaluation. Here’s a quick breakdown:

  • Vital signs like blood pressure, breathing rate, heart rate, and body temperature will be checked.
  • Weight will also be measured.
  • Oxygen levels will be checked using a device called a pulse oximeter.
  • Intravenous (IV) drip, which will delivers necessary medications and anesthesia, is attached.
  • Anticoagulants, which are blood-thinning drugs, are administered.
  • Anesthesia will put you to sleep for surgery; you’ll consult with an anesthesiologist, who’ll determine the best dosage.

During the consultation with the anesthesiologist, you’ll get a final chance to ask any questions; never hesitate to voice these to medical staff. Before you’re taken into the operating room, you’ll also be asked to empty your bladder, undress, and to give any valuables to your loved ones.

During the Surgery

Most often, gastric sleeve surgery is done laparoscopically—that is, employing a retractable camera and removing tissues through a tube placed in your body. All told, about 75 to 80% of the stomach is taken out, with the remaining portion being formed into a pouch.

This reduces the amount of food you can eat at one time, while also lowering overall appetite and sensation of hunger. This work is performed by surgeons specializing in weight loss surgery, as well as support staff.

How’s it done? Here’s a quick breakdown:


You’ll first be put to sleep so that surgery isn’t felt; it’s not performed with the patient awake. Aside from the pinch when you’re connected to the IV, you’ll feel no pain. As you get to the operating room, you’ll also be connected to machines monitoring vital signs, as well as a respirator to help you breathe.


Small incisions are made into the abdominal wall, to allow the laparoscope, surgical tools, and tubes to the stomach. At 15 millimeters (mm), the largest of these is the stomach extraction port located above and to the right of your belly button, followed by the 12 mm camera port to its left.

Several other smaller incisions allow in tools to help position the liver and perform the operation.


Prior to work beginning in earnest, the surgeon observes the area through the laparoscope, then starts to split away the blood supply from the portion of the stomach to be removed. This is an essential step that ensures a safe procedure.

Dividing the Stomach

Once the blood supply is divided, a special tube, called a Bougie tube is placed in the stomach to serve as a sizer for the portion that’s left in the body. Then, a specialized stapler is used to split the stomach into two.

Forming the Pouch

After ensuring that the part of the stomach that remains—about 20% to 25% of the original—is properly stapled shut, the rest of the tissue is taken out through the stomach extraction port.

Once the procedure is completed, the incisions are dressed and shut. Sometimes, a tube running through the nose to the stomach will be left in to allow surgeons access to the area to ensure it’s healing well.

After the Surgery

Given the scope of gastric sleeve surgery, it’s little wonder that you can expect a one- to two-night stay in the hospital following gastric sleeve surgery. This is a critical time as your surgeon will need to ensure that there are no complications and that your stomach is healing well.

You’ll feel some pain and soreness following the operation. You’ll be administered pain managing medications throughout your stay.

What does recovery in the hospital look like? When can you go home? Here’s a rough timeline:

Transfer to Post-Operative Recovery

The patient is typically taken to a post-operative recovery room once they start waking up from anesthesia, though sometimes they’re already there when they wake.

Your bladder will be connected to a catheter during the procedure, and this will usually be left in until the day after surgery (sometimes longer). Once breathing is back to normal, along with other vital signs, you’re transferred to a monitored recovery room.

In the Monitored Recovery Room

Before you’re taken to a regular hospital room, you’ll be in a room specially designed to monitor you as you recover. Most patients are here for at least a day following surgery.

During this time and throughout the hospital stay, you’ll have to wear specialized compression stockings to help with blood circulation and prevent blood clots. If everything looks good in terms of recovery, you’ll then be transferred to a regular hospital room.

In-Hospital Recovery

As you’re recovering, it will be critical that you get some activity. You’ll be asked to get out of bed and walk around—usually with assistance—the evening of surgery day. In addition, throughout your time in the hospital, you’ll be asked to walk around the halls regularly.

During this time, too, you’ll be asked to use an instrument called an incentive spirometer that measures your breathing. As you’ll be instructed, it’s important to take 10 deep breaths into this device once every hour.  


Before you’re clear to go home, your surgeon will need to ensure that the surgery is successful and that your body is recovering well.

Several important tests are performed, including a full metabolic panel every 12 hours for the first day after surgery, and once daily after that. This assesses blood, liver, and kidney health, all of which are important markers of a successful surgery.

In addition, if your surgeon believe there’s a risk of a blood clot, they’ll use ultrasound monitoring. They will also observe for signs of a leak from the newly formed pouch. 


If there are no signs of complications, and healing is progressing healthily, you’ll be clear to go home. As noted, patients usually require two nights in the hospital for recovery.

At discharge, you’ll be given a great deal of guidance on diet and exercise that’s critical for a successful outcome. Arrange for a ride home, and be sure to come back in for the follow-up appointment (typically about two weeks afterward).

Post-Operative Diet

Since surgery takes place on the stomach, it’ll be some time before you’re able to eat solid foods. As you’ll be counseled, the post-operative diet during initial recovery is liquid-based and highly regimented:

  • The first 24 hours in the hospital are particularly delicate, and you won’t be able to eat or drink anything during this time. You’ll get nutrition and fluids via IV.
  • Day two after surgery is when, barring complications, you’ll be allowed to drink water and clear juices.
  • At discharge you’ll get full counseling on the liquid-based diet you’ll need to follow. You won’t be able to eat solid foods for at least two weeks and only when the surgeon has deemed it safe. 

It’s absolutely essential that you stick to your surgeon’s orders with regards to diet and exercise. Gastric sleeve surgery, by itself, does not cause weight loss; rather, it sets up the conditions for successful outcomes based on changes you have to make. Be sure you’re clear on what you should be eating, drinking, and doing following the operation.

Gastric sleeve surgery is very safe and highly-successful, with 60% to 70% of excessive weight expected to be lost within the first year after the operation.

A Word From Verywell

While the prospect of weight loss surgery may be intimidating, it’s important to remember that this procedure is both very safe and highly successful in promoting positive outcomes. It’s highly successful in combatting not only obesity and a range of related conditions, while promoting a healthier quality of life.

Well tolerated, it’s no wonder that this is the most popular form of bariatric surgery performed in the U.S. and abroad. While the road to good outcomes only begins with gastric sleeve surgery, with the right healthcare providers and support from loved ones, it can become the first step in an important journey. 

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Kaiser Permanente Department of General Surgery. Steps towards a healthier future: bariatric surgery program guide. 2020. 

  2. UCLA Bariatric Surgery. What is sleeve gastrectomy?.

  3. Columbia University Department of Surgery. Your surgery: from planning to post-operative care.

  4. Elrazek A, Elbanna A, Bilasy S. Medical management of patients after bariatric surgery: principles and guidelinesWorld J Gastrointest Surg. 2014;6(11):220.

  5. Cleveland Clinic. Gastric sleeve surgery. 2020. 

By Mark Gurarie
Mark Gurarie is a freelance writer, editor, and adjunct lecturer of writing composition at George Washington University.