What To Eat After A Colonoscopy – Registered Dietitian Advice

Are you wondering what to eat after a colonoscopy?

Although most people recover quickly after a colonoscopy, nourishing your body with the appropriate post-colonoscopy diet can promote a smooth transition back to your regular bowel habits.

It can be very confusing when looking for information about what to eat after a colonoscopy because advice varies from doctor to doctor, without a clear consensus.

The advice varies because there is no research to base it on. Instead, every doctor or dietitian is going off their own clinical experience.

This article serves as a guide, offering insights and recommendations on what to eat after a colonoscopy based on our experience.

It also provides a list of foods to include in your post-colonoscopy diet. 

While following the specific instructions provided by your healthcare provider is crucial, the suggestions presented here can assist in gradually reintroducing foods into your diet and optimising your digestive well-being.

What should you eat after a colonoscopy?

Preparing for a colonoscopy typically involves a period of fasting and bowel cleansing to ensure that the colon is clear for the procedure. This gives the camera a clear path to see if there is any damage in the gut.

This ‘clear-out’ process plus the sedation from the procedure can make your gut a little sensitive. Below we answer the question ‘what should you eat after a colonoscopy’ in a step by step manner as your gut recovers.

What should you eat after a colonoscopy –  0-1 hour after 

You can drink some fluids shortly after you wake up from the procedure. Initially, these would be clear fluids which rehydrate your body. 

Examples of clear fluids to include in your post-colonoscopy diet are:

• Water
• Clear fruit juices (without pulp)
• Tea without milk
• Clear broths
• Isotonic drinks

Isotonic drinks are often recommended at this phase as they contain a balanced combination of water, carbohydrates, and electrolytes (such as sodium, potassium, and magnesium) in proportions similar to those found in the body.

This combination is optimal for rehydration. You will likely be dehydrated after the colonoscopy due to being unable to drink for hours and losing fluids from the bowel preparation for the procedure. Taking isotonic drinks here can help you rehydrate effectively (1).

Taking clear fluids after the procedure is low risk and allows your healthcare provider to check that your gut is functioning as it should be and has woken up from sedation.

The recommended time might vary for how long you stay on clear fluids (before adding foods) as it will depend on your symptoms and individual factors such as medical history.

Diet 2-4 hours after colonoscopy

If there are no issues with clear fluids, your doctor may advise that you can move to food, which can be your regular diet.

However, when reintroducing foods into your diet after your colonoscopy, avoiding certain items that could irritate your digestive system is advisable.

Here are some foods to avoid during the initial phase after a colonoscopy:

• Spicy foods: Spicy food can irritate the sensitive lining of your colon, especially if this is usually a trigger for your IBS symptoms (2) 
• Greasy or fried foods: Greasy or fried foods can be heavy on the stomach and may cause some nausea after sedation.

Alcohol: Alcohol is likely to irritate the lining of your gut and may contribute to dehydration (2)

Day 1-2 after colonoscopy

By this point, you will usually eat your regular diet. However, staying well-hydrated is crucial after a colonoscopy as you will not have been able to drink anything for several hours before your procedure and lose water when using laxatives to clear the gut (3). 

These factors combined can cause dehydration. Dehydration may also have a knock-on effect of causing you to become constipated, as less water availability means your stools will be harder. 

In addition to drinking enough water, you can include hydrating foods in your post-colonoscopy diet. Some examples of hydrating foods to include as part of your diet after a colonoscopy include:

• Water-rich fruits: Watermelon, grapes, and citrus fruits like oranges and grapefruits are excellent choices. They not only provide hydration but also contain essential vitamins and minerals.
• Soups
• Smoothies

Constipation post-colonoscopy

Some people may find themselves constipated after a colonoscopy. This may be attributed to the following reasons:

• Dehydration (discussed above). 
• Following low fibre diet in preparation for colonoscopy
• Sedation from the procedure.

Effects of sedation on bowel habits

Sedation may also be used during the colonoscopy to help alleviate discomfort or pain. Some people may have a sedative IV, while others have gas and air. These tend to make you relaxed but not asleep.

Taking sedatives can have several effects on the gut. However, the impact can vary depending on the type of sedation used and the dosage. It may also depend on individual factors such as age.

Generally, sedatives can slow down the movement of the gastrointestinal tract, including the stomach and intestines. This can lead to decreased bowel activity and a temporary slowdown of digestion, leading to constipation in some people (4).

It’s important to note that the effects of sedation on the gut are generally temporary and reversible. Once the sedative wears off, normal gut function typically resumes.

How to manage post-colonoscopy constipation

You should speak to your doctor if you still struggle with constipation a few days after the procedure. 

Reaching the recommended amount of 30g of fibre in your diet can help manage constipation along with adequate fluid intake (5). However, speak to your doctor about laxatives if needed.
You can read more about this in our blog: What is constipation and how should you treat it?

What is a colonoscopy?

A colonoscopy is a medical procedure involving examining the colon and rectum using a flexible tube with a camera to screen for abnormalities or diagnose certain conditions.

A colonoscopy is essential for early detection, prevention, and treatment of various gastrointestinal conditions. Regular screening is recommended for individuals at risk or as part of routine preventive care. (6)

Before the procedure, a preparation process is followed to cleanse the colon, which involves dietary modifications and laxatives. If you have an upcoming colonoscopy, read our blog post here: What to expect when you have a colonoscopy.

Consult with your healthcare provider to determine the appropriate timing and frequency of colonoscopy based on your health history, risk factors, and medical guidelines.

Summary

An appropriate post-colonoscopy diet can optimise your digestive well-being by nourishing your body with suitable foods and avoiding potential irritants.

Managing the risk of constipation post-colonoscopy is vital. Drinking fluids, eating fluid-rich foods, and re-introducing your fibre intake post-colonoscopy should help. However, if you are struggling, contact your GP – they may prescribe laxatives.

Please note that the above advice is based on our clinical experience of post- colonoscopy diet needs. 

Your doctor may advise a different routine based on your personal situation. In this scenario we would advise that you follow this guidance.

Written by Annabelle Green Registered Dietitian, reviewed by reviewed by Kirsten Jackson, Consultant Dietitian BSc Hons, RD, PG Cert