A GLP-1 Before Surgery or a Colonoscopy: My Questions Before Booking

Before booking the procedure

Most patients can continue their GLP-1 before elective surgery or a procedure, according to the multi-society guidance summarized by the American Society of Anesthesiologists. That is not permission to ignore the instructions from your own team. Tell the procedural team what you take, the dose, your last dose, and any stomach symptoms early enough for them to make a plan¹.

My practical concern is simple: I would rather sort out the medicine instructions before arranging a ride, childcare and a day off. A cancellation after all of that is more than an inconvenience.

Why an empty stomach is part of the conversation

GLP-1 medicines can slow stomach emptying. Under general anesthesia or deep sedation, stomach contents can enter the lungs. The risk is called aspiration. My usual overnight fast might therefore not answer the whole question¹.

Put the drug on the medication list even if it is prescribed for weight management rather than diabetes. Name a compounded medicine explicitly too. A brand-name checklist is not a reason to leave out the active ingredient.

The useful distinction for me is between the person who books the appointment and the clinician who sets the anesthesia plan. I want confirmation that the latter has actually received the list. Sending a portal message to my prescriber alone does not tell me what the procedure center knows.

Why two instruction sheets may disagree

Older advice often said to hold a weekly GLP-1 for a week. The newer multi-society approach is more individualized. A separate 2025 consensus statement also supports continuing treatment in patients without significant symptoms, while recommending changes to fasting. These documents are not identical².

Conflicting instructions need clarification. Send both sets to the procedure team and ask for one dated plan. That is especially important if the printed paperwork predates a medication change.

My question would be: “You know I take this medicine. Does this fasting and medication schedule still apply to me?” I would want the answer in writing so I can follow it when the actual preparation starts.

Details the team needs

The ASA identifies starting treatment or increasing the dose, gastrointestinal symptoms, and other conditions that slow stomach emptying as reasons for extra assessment. Depending on the situation, a team may use a liquid-only preparation period, assess the stomach with ultrasound, change anesthesia plans, or delay an elective procedure¹.

Report nausea, vomiting, constipation and abdominal discomfort honestly. A difficult week should not become “fine” just to keep an appointment. My note would include when symptoms began, whether I can drink normally, and when I last increased the dose.

Ask what the center means by liquids. A protein shake, clear broth and water are not interchangeable just because all three can be poured. I need the center's permitted-drink list and cutoff times, not a menu I assembled from social media.

The colonoscopy has a second set of instructions

For a colonoscopy, ask about both sedation and bowel preparation. The laxative schedule is its own instruction set. I would not replace it with the anesthesia fasting rules or assume a longer fast makes a missed preparation step harmless.

If the preparation makes me repeatedly vomit, or I cannot complete it, I would call the endoscopy service. I would also ask which number works after hours before starting. That is more helpful than searching for a number while feeling sick.

My stomach-pain guide separates routine discomfort from symptoms that deserve medical attention. Severe or persistent abdominal pain, trouble breathing, fainting, or inability to keep fluids down deserves prompt medical assessment, not an attempt to finish the prep at all costs.

Plan the first dose afterward too

Before discharge, ask who decides when treatment restarts, particularly if I am not eating normally or have missed several doses. My old dose is not automatically the right restart dose after an interruption. The same question applies if the team changes other diabetes medicines while I am there.

For an emergency operation, I would not delay urgent care to wait for a drug to leave my system. I would tell the emergency team what I take and when. My job is to bring accurate information; the anesthesia plan belongs to the clinicians caring for me.