3 days before your colonoscopy
Colonoscopy diet advice and bowel preparation
Please make sure you follow these instructions 3 days before your colonoscopy.
Medicines
Stop taking any medicines that contain:
- codeine phosphate (which is used to treat pain, a cough and diarrhoea)
- loperamide (which is used to treat diarrhoea)
There should be a list of what your medicines contain in the leaflet that comes with them.
If you are not sure whether your medicines codeine phosphate or loperamide, please ask your pharmacist, doctor or nurse. You can also call our pharmacy medicines helpline on 020 7188 8748, Monday to Friday, 9am to 5pm.
Continue to take all other medicines as usual.
Food and drink
Drink plenty of fluids. Try to drink 2 litres (about 8 to 10 glasses) in a day.
You will need to start eating a low fibre diet from the morning. Continue to eat a low fibre diet the next day.
Eat only the low-fibre foods in this list.
You can eat or drink
- Well cooked, lean (low fat) beef, lamb, ham, veal or pork
- Fish, shellfish or poultry
- Boiled or poached eggs
- Soya or tofu
- White rice, noodles or white pasta
- Cereal including cornflakes and crisped rice cereal, but not bran
- White bread or toast
- Potatoes without the skins (boiled, creamed, mashed or baked)
- Butter, margarine or cheese
- Milk, cream or cottage cheese
- Vanilla ice cream
- Custard
- Plain yoghurt
- Plant-based milk and yoghurt
- Gravy made only from stock cubes (you can use plain flour or cornflour to thicken this)
- Sugar or sweetener
- Honey
- Golden syrup
- Rich tea biscuits, plain biscuits, rice crackers
- Boiled sweets
- Plain sponge cake
- Clear jelly
- Water, cordial, fizzy drinks, fruit squash
- Clear strained soup or clear stock
- Clear fruit juice (without pulp)
- Herbal tea
- Tea or coffee
Do not eat
- Pulses or lentils
- Nuts or seeds
- Brown rice or brown pasta
- High-fibre breakfast cereals (including porridge)
- High-fibre, multi-seeded, 50/50 or wholemeal bread
- Potatoes with skin, or roasted, deep fried potatoes (including chips)
- Crisps
- Jam
- Gravy granules (as may contain fibre)
- Red jelly
- Alcohol
- Red cordial or red fruit juice, blackcurrant juice
- Fruit juice that's not clear (juice with pulp)
- Fruits (fresh, dried or canned)
- Vegetables
- Any soups with vegetables, lentil beans or “cream of’’ soups
Resource number: 3993/VER3
Last reviewed: December 2025
Next review: December 2028
