You have a colonoscopy, a hernia repair or a wisdom tooth booked, and you take one of the weekly injections prescribed for weight. Between now and the date, three separate sets of people make decisions about you: the clinician who prescribes the injection, the surgeon or gastroenterologist or dentist doing the procedure, and an anesthesia team you have not met. None of them automatically knows what the others know.
The instruction printed on these medicines is to tell your healthcare providers before any planned surgery or procedure. Here is who that means in practice, how far ahead of your date to say it, and what changes when you leave it late.
Yes, they need to know, and the moment to tell them is the day the procedure is booked rather than the week of it. These medicines slow the stomach down, and there are rare reports of people arriving for procedures with food still in the stomach after following the fasting instructions exactly. Told early, the plan can be adjusted in advance. Told when you arrive, the choices narrow to what can be done in the next hour, and one of them is sending you home.
Why an anesthesia team cares about a weight medicine
An anesthesia team cares about a weight medicine because this kind of medicine slows the stomach down, and an empty stomach is what makes deep sedation safe. Deep sedation and general anesthesia switch off the reflexes that keep stomach contents out of the lungs, which is the reason you are asked not to eat or drink after a set time the night before.
In November 2024 the labeling for the FDA-approved products in this class gained a warning, recording rare reports of stomach contents reaching the lungs during elective surgery or procedures under general anesthesia or deep sedation, in people who had followed their fasting instructions. What to do about the medicine is decided case by case, and the only part of it that belongs to you is saying what you take.
Some situations carry more risk than others. The ones named in the joint perioperative guidance from the anesthesia, surgery and gastroenterology societies include taking a weekly medicine rather than a daily one, having started or changed it recently, and having stomach symptoms in the days beforehand — among them nausea, vomiting, stomach pain and constipation. Mention any of those by name when you call, because they change what your team plans.
Who to tell, and how far ahead
Tell three people, and tell them when the date is set rather than when the pre-op call comes: the clinician who prescribes the injection, whoever is performing the procedure, and the anesthesia team or pre-op nurse who contacts you beforehand.
The schedule is what makes the timing matter. The checkup before surgery usually happens within the month before it, and you may not meet the anesthesia provider until the week before — some hospitals handle that part by phone, with a pre-op nurse rather than the anesthesia provider in person. Anything that takes a full day of preparation, or a different slot on the operating list, has to be settled before then.
What to say is one sentence: you take a weekly injection for weight, and you want to know what the site wants done about it ahead of the date. Write the answer down along with the name of the person who gave it, and repeat it when the pre-op call comes — the person who answers you today may not be the person who calls you the week before.
What they may change, and what happens when they hear on the day
What a team may change is small, and all of it is easier to arrange in advance: a full day of clear liquids only, a bedside ultrasound scan of the stomach on the day to see whether it is empty, or a method of putting you under that protects the airway from the first moment. Carrying on unchanged is also among the listed options, for a patient the team does not judge to be at raised risk. Whether anything is paused at all is a shared decision between you and the procedural, anesthesia and prescribing teams.
Say it on the morning and the same decisions still have to be made, in a corridor, with nothing prepared. What is left is a bedside ultrasound if the site owns one, a change of technique, a later slot, or a canceled procedure — which for a colonoscopy means a second bowel preparation and a second day off work.
The one sentence that does not help on arrival is I followed the fasting instructions. So had the patients in the reports that put the warning on the label.
When to call ahead, and when to call emergency services
Call your prescriber before the date, rather than on it, if you are vomiting, cannot keep fluids down, or have stomach pain that is new or severe. Those symptoms change what the anesthesia team plans, and they are also the ones that get a procedure postponed on arrival.
After any sedation, stomach contents that reached the lungs can cause a chest infection over the days that follow. Go to an emergency room or call 911 for chest pain, chills, fever, shortness of breath, wheezing, or a bluish color in the lips or tongue. Coughing up dark, bloody or foul-smelling phlegm, trouble swallowing and confusion belong on the same call.
The two calls to make today
- Call the department that booked the procedure. Say you take a weekly injection for weight, and ask what they want done about it ahead of the date.
- Message your prescriber that the procedure is booked, and ask the same question.
- Write down the answer and who gave it, and repeat it to the pre-op nurse or anesthesia team when they contact you.
- Bring a list of every medicine you take on the day, including anything you were told to stop.
- Report nausea, vomiting or stomach pain in the days beforehand instead of waiting to be asked about it.
The medicine, the procedure and you are three facts, and only your three teams hold all of them at once. Quite often what comes back is carry on exactly as you are — a real answer, not a brush-off, and worth the call to get. Ask it now and it costs a phone call. Ask it on the morning and it can cost you the appointment.
