Preparing for day surgery: fasting, anaesthesia and going home the same day

A generation ago, an operation meant a hospital bed and several days on a ward. Today a large share of surgery — hernia repairs, gallbladder removal, endoscopy, vein procedures, excision of skin lumps — is done as day surgery: you arrive in the morning, have the procedure, recover for a few hours, and sleep in your own bed that night.

Done well, day surgery is not a compressed version of hospital care but a carefully planned pathway. This guide covers what patients most often ask me about preparing for day surgery: the fasting, the anaesthesia options, and what to organise before and after.

What day surgery actually means

Day surgery is planned, not improvised. Before a procedure is booked as a day case, two things are assessed: whether the operation itself is suited to same-day discharge, and whether you are — your general health, your other medical conditions, and whether there is someone at home with you on the first night.

Many of the operations in my general surgical practice — hernia repair, keyhole gallbladder removal, skin lump excision — are done this way in suitable patients, as are gastroscopy and colonoscopy, which I perform at MOH-accredited day surgery and endoscopy centres.

Why you are asked to fast

Fasting has nothing to do with the part of the body being operated on. It is about the anaesthesia. Sedation and general anaesthesia relax the reflexes that normally keep stomach contents out of the airway, and an empty stomach is what protects the lungs while you are asleep or deeply drowsy.

The exact times vary — commonly no food for around six hours beforehand, with clear fluids allowed until closer to the procedure — but the instruction that matters is the one your own team gives you, tailored to your procedure and anaesthetic. Follow it precisely: arriving with a full stomach usually means the operation is postponed, because proceeding would not be safe.

Local, sedation or general — in plain English

There are three broad options, matched to the procedure and to you:

• Local anaesthesia numbs the operative area with an injection while you stay fully awake. Skin lumps and cysts are commonly removed this way. Some procedures need no anaesthetic at all: I perform sclerotherapy for spider veins and smaller varicose veins in the clinic with very fine needles, and patients walk out straight afterwards.
• Sedation is medicine given through a drip that makes you drowsy or lightly asleep. It is how gastroscopy and colonoscopy are done — most patients sleep through the procedure and remember little of it. You breathe for yourself throughout, but the fasting rules still apply.
• General anaesthesia puts you fully asleep, with an anaesthetist managing your breathing and monitoring you throughout. Keyhole operations such as hernia and gallbladder surgery are usually done this way.

Each has its place. The choice is part of the surgical planning, and it is a conversation — not a form to sign.

What to arrange in the week before

• An escort home. After sedation or general anaesthesia you cannot drive, and most centres will not discharge you without a responsible adult to accompany you. Arrange this early — it is a common logistical snag.
• Time off. Ask how much recovery your specific procedure typically needs — a day or so after endoscopy, longer after hernia or gallbladder surgery — and secure the leave in advance rather than negotiating it afterwards.
• Your medication list — especially blood thinners. Aspirin, clopidogrel, warfarin and the newer anticoagulants may need adjusting before surgery, and the decision is individualised: never stop them on your own. Flag them at the consultation, along with diabetes medications — fasting changes the dosing — and any supplements you take.
• Practicalities. Loose comfortable clothing, no jewellery or valuables, someone at home with you the first night, and easy meals in the fridge.

The day itself, step by step

Registration and identity checks come first, then a run through your fasting times, the consent discussion and any last questions. You change, the anaesthesia is given, and the procedure is done. You then move to a recovery area where nurses monitor you until you are fully awake — typically an hour or two, sometimes longer after a general anaesthetic.

Discharge follows a checklist rather than a clock: awake and steady on your feet, comfortable, able to drink, and clear on your wound care, medications and follow-up appointment. You leave with written instructions and a contact number for problems.

The first 24–48 hours

Expect to feel tired and a little foggy on the first day — sedation and general anaesthesia typically take about a day to clear fully. For the first 24 hours: no driving, no alcohol, no signing of important documents, and no operating machinery.

Some soreness at the operative site is normal and should be controlled by the painkillers you are sent home with; most patients find each day noticeably easier than the last. Follow the specific instructions you are given on wound care, showering and activity.

Contact your surgical team promptly — or attend an emergency department — if you develop fever, spreading redness or discharge at the wound, bleeding that does not settle with pressure, pain that is worsening rather than easing, persistent vomiting, or difficulty passing urine. Day surgery works because the right patients are chosen and problems are picked up early — and the picking up is a job you and your surgeon share.