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Ask an Expert: Bariatric Surgery – What to expect on the day

Bariatric procedure

Undergoing surgery can be a nerve-wracking experience, filled with anxiety and numerous questions about what to expect. Understanding the process can help alleviate some of these concerns. In this blog, Clinical Director of Streamline and Bariatric Surgeon, Guy Slater, provides an overview of what typically happens on the day of bariatric surgery in the uk, from the moment you wake up to when you find yourself back in the ward post-operation.

Pre- bariatric surgery preparations

Nil by mouth:

If your surgery is scheduled for the morning, you’ll need to fast from midnight the night before. For afternoon operations, the fasting period starts early in the morning. This means no food or drink to ensure your stomach is empty, reducing the risk of complications during anaesthesia.

The night before:

It’s common to have a restless night before surgery. Anxiety mixed with excitement is a typical emotional cocktail. Try to rest as much as you can.

What to bring:

Don’t forget to bring any regular medication you take, along with your CPAP machine if you use one for sleep apnea. These will be crucial for your comfort and health before and after the procedure.

Arrival at the hospital

Drive to the Hospital:

On the morning of your surgery, you’ll drive to the hospital, possibly feeling a mix of anxiety and anticipation.


Upon arrival, a porter will escort you to the ward where a nurse will officially admit you. This involves a health check and answering a lot of questions to ensure everything is in order.

Meeting your medical team


You will meet with both your bariatric surgeon and anaesthetist before the operation. They will review the procedure, explain the risks, and answer any last-minute questions you may have. You will also sign a consent form at this stage, confirming your agreement to proceed with the surgery.

The waiting game

Pre- bariatric surgery wait:

There can be a variable amount of waiting time before you are taken to the operating theatre. This waiting period is a good time to try and relax, although it’s easier said than done. Typically, you will walk down to the theatre accompanied by a nurse.

In the operating theatre


Once in the theatre, you will be anaesthetised. An intravenous cannula will be placed in your arm, through which intravenous drugs will be administered to induce anaesthesia while you breathe in oxygen.

During the operation

Bariatric surgery duration:

The duration of the operation varies. For a gastric sleeve, it usually takes about an hour, while a gastric bypass might take around two hours. However, you will be off the ward for a longer period, typically about 3-4 hours, to account for preparation and recovery time.


Recovery room:

After the operation, you will wake up in the recovery area where you will be closely monitored for approximately an hour. This is to ensure that you are waking up safely from the anaesthesia and that your vital signs are stable.

Back to the ward:

Once cleared from the recovery area, you will be returned to the ward. Your partner or a loved one can be present at this time, providing much-needed comfort and support. Expect to feel very sleepy and possibly uncomfortable. Nausea is also common but manageable.

The first 12 hours post- bariatric surgery

Initial recovery:

Within the first 12 hours, you should start to feel much better. Pain is usually well controlled with medication, and many patients report little to no pain. You’ll begin drinking fluids satisfactorily and experience minimal nausea.

While the day of surgery is undoubtedly challenging, understanding the process can help ease some of your anxieties. Remember that the medical team is there to support you every step of the way, ensuring your safety and comfort. Keep communication open, ask questions, and trust in the expertise of your healthcare providers. The journey may be daunting, but it’s a significant step towards better health and well-being. 

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