Which test are you having?
| Test | What it looks at | Preparation | Usual time |
|---|---|---|---|
| Upper GI endoscopy (gastroscopy, UGIE) | Food pipe, stomach and first part of the small intestine — through the mouth | Empty stomach | 5–15 minutes |
| Colonoscopy | The whole large bowel — from below | Low-fibre diet + bowel-cleansing medicine | 20–45 minutes |
| Sigmoidoscopy | The last part of the large bowel only | Usually an enema shortly before | 10–15 minutes |
All three are done at Hayat Hospital and Apollo Clinic, Ulubari. A thin flexible tube with a camera is used; small tissue samples (biopsies) can be taken painlessly, and small polyps can often be removed during colonoscopy.
Most tests are done without sedation — they are quick and well tolerated. Sedation is available on request at Hayat Hospital (see below).
Upper GI endoscopy — preparation
- Nothing to eat for 6 hours before the test. Plain water is usually allowed until 2 hours before — you will be told the exact time.
- Morning medicines: blood pressure, thyroid and heart medicines can usually be taken with a small sip of water early in the morning.
- Diabetes: do not take diabetes tablets or insulin while fasting unless advised — see the diabetes section below.
- Bring previous endoscopy reports, biopsy reports and a list of all your medicines.
- Come with a family member — this is essential if you choose sedation.
Colonoscopy — preparation
Why the preparation matters: the bowel must be completely clean for the doctor to see small polyps and early growths. If the bowel is not clean, important findings can be missed and the test may have to be repeated — with the preparation all over again.
Timeline
| When | What to do |
|---|---|
| 7 days before | Tell us about blood thinners, diabetes medicines and weight-loss injections (see below). Stop iron tablets — they make the bowel harder to clean. If you are often constipated, tell us: an extra day of preparation may be advised. |
| The day before — until afternoon | Eat a low-fibre diet (list below). Avoid seeds, leafy greens and fruit with skins or seeds. |
| The day before — evening | Clear liquids only. Take the first part of the bowel-cleansing medicine at the time on your prescription. |
| The day of the test | Take the second part of the medicine, usually 4–6 hours before the test. Finish all of it at least 2 hours before your appointment. Clear liquids only until then. |
Splitting the medicine between the evening before and the morning of the test cleans the bowel best. For a morning or afternoon slot, the timing is adjusted — follow the schedule given with your booking.
Low-fibre diet — the day before
Clear liquids — allowed after the low-fibre lunch
- Water, ORS, coconut water, clear soup (strained, no pieces), lemon water, glucose water
- Black tea or black coffee — no milk
- Avoid milk, lassi, juice with pulp, and red or purple drinks (they can look like blood)
Taking the bowel-cleansing medicine
- Drink it chilled and through a straw, a glass every 10–15 minutes. Sucking a lemon slice between glasses helps.
- Keep drinking clear liquids alongside to stay hydrated — especially older patients.
- It is working when you pass clear or pale-yellow watery stool with no solid bits.
- If you feel sick or vomit, pause for 30–60 minutes, then continue more slowly. If you cannot finish it, message us — do not simply skip the test.
- Stay near a toilet. Applying coconut oil or petroleum jelly around the back passage prevents soreness.
- People with kidney disease, heart failure or who are frail may need a specific type of preparation — tell us when booking.
Diabetes, blood thinners and other medicines
| Medicine | Usual advice |
|---|---|
| Diabetes tablets | Skip on the morning of the test while fasting; restart with your first meal. |
| Insulin | The dose is usually reduced on the preparation day and the morning of the test — ask for your exact dose. Check your sugar more often; if it goes low, take glucose water or a clear sugary drink. |
| Aspirin, clopidogrel, ticagrelor | Usually continued for a diagnostic test. If a polyp removal is planned, some may be paused — the plan is made with your heart doctor. |
| Warfarin, apixaban, rivaroxaban, dabigatran | Depends on the test and the reason you take them. Always tell us in advance so a plan can be made. |
| Weight-loss or diabetes injections (semaglutide, tirzepatide, liraglutide) | These slow stomach emptying. You may be asked to take only liquids for 24 hours before the test — tell us when booking. |
| Iron tablets | Stop 7 days before a colonoscopy. |
Never stop a blood thinner on your own — stopping some of them suddenly can cause a heart attack or stroke.
With or without sedation?
| Option | What it involves | Where |
|---|---|---|
| Without sedation (most patients) | Gastroscopy: a throat-numbing spray; brief gagging for a few minutes while you breathe normally. Colonoscopy: some cramping as air is passed, which eases quickly — the doctor can pause at any time. You go home soon after and can usually return to work the same day. | Hayat Hospital and Apollo Clinic, Ulubari |
| With sedation (on request) | Medicine through a drip makes you drowsy and relaxed, with breathing, oxygen and heart rate monitored. You need a family member to take you home and must rest for the rest of the day. | Hayat Hospital only — ask when booking |
- After sedation, do not drive, ride a two-wheeler, operate machinery or sign important documents until the next day.
- Women can have a colonoscopy during their period — it does not affect the test.
Booking an endoscopy or colonoscopy?
Message us on WhatsApp with your reports and a list of your medicines. You will receive the exact preparation instructions and timings for your slot — at Hayat Hospital or Apollo Clinic, Ulubari.
After the test
- Bloating and passing gas after colonoscopy is normal — walking helps it settle.
- After a throat spray, wait about an hour before eating or drinking.
- You can usually eat normally the same day, unless told otherwise after a polyp removal.
- The findings are explained before you leave. Biopsy and polyp reports usually take about a week; your next check-up or repeat colonoscopy is planned from them.
Risks
Diagnostic endoscopy and colonoscopy are very safe. The figures below are from large published studies.
| Complication | How often |
|---|---|
| Bleeding after polyp removal | About 1 in 100–200; usually small and often stops on its own |
| Perforation (a tear) during colonoscopy | About 1 in 1,000–3,000; higher when large polyps are removed |
| Perforation during diagnostic gastroscopy | Very rare — fewer than 1 in 10,000 |
| Breathing or heart problems with sedation | Uncommon — and only relevant if sedation is used; monitoring is continuous |
Get medical help urgently if after the test you have:
- Severe or worsening tummy pain, or a hard, swollen tummy
- Fever or shivering
- Passing more than a few spoonfuls of blood from the back passage, or black stools
- Vomiting blood, chest pain or breathlessness
Call us, or go straight to the nearest emergency department. Bleeding after polyp removal can appear up to 2 weeks later.
Common questions
Is endoscopy or colonoscopy painful?
Most tests are done without sedation and are well tolerated. Gastroscopy uses a throat-numbing spray and causes brief gagging for a few minutes. Colonoscopy can cause some cramping, which eases quickly, and the doctor can pause at any time. Sedation is available on request at Hayat Hospital.
Can I have sedation?
Yes, on request at Hayat Hospital. Tell us when booking. With sedation you need a family member to take you home, and you must not drive or ride a two-wheeler until the next day. At Apollo Clinic, Ulubari, tests are done without sedation.
Can I drink water before an endoscopy?
Usually yes, plain water until 2 hours before the test. Food must be stopped 6 hours before. Follow the exact times given with your booking.
How do I know my bowel preparation has worked?
Your stool should be clear or pale-yellow liquid with no solid bits, like urine. If it is still brown or has particles close to your appointment time, message us before coming.
What if I vomit the bowel preparation?
Pause for 30 to 60 minutes, then continue more slowly, sipping through a straw. If you still cannot finish it, message us — the test may need to be rescheduled or the preparation changed.
Can I take my blood pressure and thyroid medicines?
Yes. Take them early in the morning with a small sip of water. Diabetes medicines and blood thinners need specific advice.
I take semaglutide or a similar injection. Does it matter?
Yes. These medicines slow stomach emptying and can leave food in the stomach even after fasting. You may be asked to take only liquids for 24 hours before the test. Tell us when booking.
Can I go back to work the same day?
Most patients have the test without sedation and can return to work the same day. If you choose sedation, rest for the remainder of the day and do not drive, ride a two-wheeler or make important decisions until the next day.
Related
Written and medically reviewed by Dr. Mayank Agarwal, MBBS, MD (Medicine), DM (Gastroenterology) · Assam Medical Council Reg. No. 19633 · Last reviewed:
This page gives general preparation advice. The instructions given to you with your booking are specific to your procedure, timing and health — always follow those, and never stop a prescribed medicine without advice.
Based on:
- Hassan C, et al. Bowel preparation for colonoscopy: European Society of Gastrointestinal Endoscopy (ESGE) Guideline – Update 2019. Endoscopy 2019;51:775–794.
- Jacobson BC, et al. Optimizing bowel preparation quality for colonoscopy: consensus recommendations by the US Multi-Society Task Force on Colorectal Cancer. 2025 (PMID 40047767).
- Veitch AM, et al. Endoscopy in patients on antiplatelet or anticoagulant therapy: British Society of Gastroenterology (BSG) and European Society of Gastrointestinal Endoscopy (ESGE) guideline update. Gut 2021;70:1611–1628.
- American Society of Anesthesiologists. Practice guidelines for preoperative fasting. Anesthesiology 2023;138:132–151.
- Multisociety clinical practice guidance for the safe use of glucagon-like peptide-1 receptor agonists in the perioperative period (AGA, ASA, ASMBS, ISPOR, SAGES), 2024.