Endoscopy diet 2025: what does the latest research say?

Endoscopic examinations, such as gastroscopy or colonoscopy, are key to accurately diagnosing digestive diseases. However, many people are unsure about the preparation and proper diet involved in these tests. As medical science continues to evolve, so do dietary recommendations to make tests as effective and comfortable as possible for patients.

This article provides comprehensive guidance on the right diet before and after endoscopic examinations, based on the latest scientific evidence for 2025. We look at what foods and drinks to eat and avoid before different types of tests, such as gastroscopy, colonoscopy and capsule endoscopy. By reading this article, you will get a clear idea of how to prepare yourself so that the test gives the most accurate results and you feel safe.

The information provided here will help to dispel any fears and uncertainties about the tests. Our experts, such as Endomedix Gastroenterology Centre specialists, stress the importance of proper preparation for a successful diagnosis. Learn about the latest recommendations so you can start the necessary tests with confidence and preparation.

What is endoscopy and why is diet important?

An endoscopy is a medical procedure in which a flexible, thin tube (endoscope) is inserted into the body with a tiny camera at the end. This allows the doctor to get a live image of internal organs such as the oesophagus, stomach or large intestine. The purpose of the scan is to make a diagnosis, take a histological sample (biopsy) or even perform therapeutic procedures, such as removing polyps.

Proper dietary preparation is essential for the success of the test. If the digestive tract is not properly cleansed, food residues or inadequate fluids may cover the surface of the mucous membrane. This makes it difficult for the doctor to detect abnormal lesions such as inflammation, ulcers or precancerous conditions. An inaccurate examination may require the procedure to be repeated, causing further discomfort and risk to the patient. Therefore, strict adherence to dietary guidelines is not only a suggestion, but a prerequisite for accurate diagnosis.

General dietary principles before endoscopic examinations

Although different endoscopic procedures require different preparation, there are general dietary rules to keep in mind.

Introduction of a low-fibre diet

It is recommended to switch to a low-fibre diet in the days before the test. Fibre is harder to digest and can slow down the emptying of the bowel, making it more difficult to cleanse the colon properly.

What should I avoid in the 3-5 days before the test?

• Vegetables and fruits with high fibre content: Raw vegetables (e.g. lettuce, peppers, tomatoes), small seeded fruits (e.g. raspberries, strawberries, kiwis), pulses (e.g. beans, lentils, peas).
• Wholegrain cereal products: Wholemeal bread, brown rice, bran crackers, oatmeal.
• Oily seeds: Nuts, hazelnuts, almonds, sunflower seeds.

Liquid consumption

Adequate hydration is key, especially for tests that require laxative administration. Drinking plenty of fluids helps prevent dehydration and supports the bowel cleansing process. However, it is important to drink only clear, non-carbonated fluids.

Licensed liquids:

• Water
• Light, filtered soup (broth)
• Filtered, fibre-free fruit juices (e.g. apple juice, white grape juice)
• Light coloured, non-carbonated soft drinks
• Clear herbal teas (e.g. chamomile)

Red, purple or dark-coloured drinks (e.g. red wine, beetroot juice, black tea) should be avoided as they may discolour the intestinal wall, which may appear as bleeding during the test.

Specific dietary recommendations for different studies

Each endoscopic procedure requires a different preparation and diet. Below we detail the latest recommendations for the most common tests.

1. Gastroscopy (gastroscopy) diet

During a gastroscopy, the oesophagus, stomach and horseshoe cage are examined. The aim is to ensure that the stomach is completely empty.

• Meals: Solid food should be avoided for at least 6-8 hours before the test. If the test takes place in the morning, this means that you should not eat dinner the night before, or only have a very light, early dinner.
• Liquid: Do not drink any fluids for 2-4 hours before the test. Small sips of water are usually allowed with medication, but always check with your doctor.
• Special cases: If a gastric emptying disorder (gastroparesis) is suspected, the doctor may prescribe prolonged fasting and fluid deprivation for up to 8-12 hours.

2. Colonoscopy (colonoscopy) diet

This test requires the most careful preparation, as the colon must be completely clean.

• 3-5 days before the test: Start the low-fibre diet as described above. Avoid seeds, wholegrain products and raw vegetables.
• The day before an inspection: On this day you can only eat liquid, fibre-free foods. For breakfast and lunch, filtered broth, fibre-free juices or light teas are recommended. You can no longer eat solid food. From midday onwards, only clear liquids may be consumed.
• Hash drive: The laxative solution prescribed by your doctor should be taken the day before the test or at dawn on the day of the test, as directed. Modern, small-volume laxatives are much more convenient than the large-volume (4-6 litre) solutions of the past. It is essential to drink plenty of clean fluids during the laxative.
• Medicines: You should stop taking iron supplements at least 5 days before the test because they can turn the stools black and form a deposit that is difficult to excrete. You should always consult your doctor about other medicines (e.g. anticoagulants).

3. Capsule endoscopy diet

Capsule endoscopy is a procedure to examine the small intestine by swallowing a small capsule with a camera.

• 24 hours before the test: A clean fluid diet is recommended. This means drinking only clear liquids such as water, filtered soups and fibre-free juices.
• Preparing the liner: To ensure adequate cleanliness of the small intestine, partial or complete laxation is usually necessary the night before the test. The European Society of Gastroenterology (ESGE) recommends the consumption of 2 litres of a polyethylene glycol (PEG) based laxative solution.
• Under investigation: You should fast for at least 2 hours after swallowing the capsule. After 2 hours you can drink a clear, non-carbonated liquid. Light, solid food is allowed from the 4th hour after ingestion.

4. Exhalation tests (e.g. lactose, fructose intolerance, SIBO)

Although not a classic endoscopic procedure, it is often performed in gastroenterology centres and requires strict dietary preparation.

• 4 weeks before the test: Avoiding the use of antibiotics.
• 1 week before the test: Stop taking prokinetic (bowel movement stimulating) medicines and laxatives.
• 12-24 hours before the test: Avoid complex carbohydrates (bread, pasta), dairy products and high-fibre foods.
• 8-12 hours before the test: Total starvation. Smoking and strenuous exercise should also be avoided on the day of the test as these may affect the results.

What can we do after the test?

The diet after the test depends on the type of intervention and whether any therapeutic intervention (e.g. polyp removal) has been performed.

• After a test without anaesthesia: If the test was not done under anaesthesia, you can usually eat and drink as soon as the local anaesthetic (if used) wears off. It is advisable to start with easily digestible foods.
• After an anaesthetic test: Anaesthesia may slow down the reaction time. It is recommended to rest on the day of the test. Start meals with light meals and avoid alcohol.
• After polyp removal: If an octopus has been removed, the doctor may prescribe a special diet for a few days. This usually involves a pulpy, easily digestible, low-fibre diet to help the intestinal wall regenerate. Avoid bloating, spicy and fatty foods.

The role of the Endomedix Gastroenterology Centre

Proper preparation and modern technology combine to ensure a successful endoscopic examination. From Endomedix Gastroenterology Centre a national network at the forefront of the latest diagnostic techniques. Their specialists have up-to-date knowledge of the latest international recommendations and provide each patient with personalised, detailed information on the diet and preparation required. The centres focus on patient comfort and safety, reducing the fear and discomfort associated with tests. Accurate diagnosis is the first step towards effective recovery, and in this Endomedix Gastroenterology Centre a reliable partner.

Frequently Asked Questions (FAQ)

1. Why avoid red foods and drinks?

Red-coloured substances may discolour the lining of the intestine, which may appear to be bleeding on examination. This can mislead the doctor and lead to an inaccurate diagnosis.

2. Can I drink coffee before the test?

In most cases coffee (without milk and sugar) is allowed the day before the test, but should be avoided on the day of the test. Always follow the specific instructions given by your doctor.

3. What happens if I don't follow the diet exactly?

Inadequate bowel cleansing prevents the doctor from thoroughly examining the bowel wall. This can result in important lesions being hidden. In such cases, the examination must be repeated at a later date.

4. How can I alleviate the discomfort caused by diarrhoea?

Drink plenty of clean fluids to avoid dehydration. It is a good idea to cool the laxative solution and perhaps flavour it with a little fibre-free, light fruit juice (if the instructions allow). Stay at home in a comfortable environment the day before the test.

The road to a successful diagnosis

Fear of endoscopic examinations often stems from uncertainty and lack of information. Following dietary recommendations based on the latest scientific findings will not only ensure the success of the examination, but also your comfort and safety. A thorough preparation can make the procedure smooth and effective.

The most important thing is to always follow the instructions of your doctor or institution, such as the Endomedix Gastroenterology Centre personalised guidance given by. If you have any questions about your diet or medication, don't hesitate to ask. Accurate diagnosis is the basis for successful treatment, and proper preparation is a key step on the way.