Quick Answers
It is generally recommended to avoid eating solid foods before and during taking magnesium citrate for colonoscopy prep. The laxative effect of magnesium citrate works best on an empty stomach. However, clear liquids like water, clear broth, plain gelatin, pulp-free juice, black coffee, and tea without milk are okay.
What is Magnesium Citrate?
Magnesium citrate is a laxative that is often used to clear the bowels before medical procedures such as a colonoscopy or surgery. It works by drawing water into the intestines, which stimulates bowel movements.
Magnesium citrate is available over-the-counter as a liquid solution. The typical adult dosage is around 10 ounces or 300 ml taken orally. It starts working in about 30 minutes to 3 hours, and effects can last for up to 12 hours.
Why Magnesium Citrate Requires an Empty Stomach
There are a few reasons why it is recommended to take magnesium citrate on an empty stomach:
1. Speeds up bowel emptying
Not eating allows the magnesium citrate to move through the gastrointestinal tract more quickly and efficiently. Food can delay the laxative effect.
2. Reduces nausea and cramping
Taking magnesium citrate while fasting helps reduce side effects like nausea, abdominal cramping, and bloating that can occur if it is taken with food.
3. Improves cleansing
An empty stomach allows the magnesium citrate to work optimally for bowel cleansing before procedures like colonoscopy. Eating can leave residual debris that could impact visibility.
What About Clear Liquids?
While solid foods are not recommended, having clear liquids while taking magnesium citrate is generally fine. Clear liquids help prevent dehydration from the fluid loss caused by diarrhea.
Acceptable clear liquids include:
- Water
- Clear broth
- Plain gelatin
- Pulp-free fruit juice like apple or white grape juice
- Black coffee or tea (without milk or cream)
- Clear sodas like ginger ale or lemon-lime soda
- Frozen popsicles without fruit or cream
Avoid any thick liquids like milk, smoothies, or juice with pulp which could leave residue behind.
What About Chewing Gum or Candy?
It’s best to avoid chewing gum or eating hard candies when taking magnesium citrate. Although they are not technically solid food, chewing stimulates digestive juices in the stomach which can start breaking down food.
This digestive process is counterproductive when trying to cleanse the bowels for a procedure. Even small amounts of swallowed saliva mixed with chewing gum or candy could interfere with the results.
Will Eating Solid Foods Impact Bowel Cleansing?
Yes, eating solid foods before or during taking magnesium citrate can negatively impact bowel cleansing needed for medical procedures like colonoscopy.
Here’s how eating can interfere with magnesium citrate effectiveness:
Leaves debris and stool behind
Eating solid food leaves additional material in the digestive tract that must be expelled. This increases the risk of retained debris that can interfere with visibility during colonoscopy.
Slows motility
Food intake triggers digestion which slows down intestinal activity. This delays the laxative effect of magnesium citrate in properly cleaning out the bowels.
Causes nausea/cramping
Eating with laxatives like magnesium citrate increases chances of nausea, abdominal cramping, bloating, and other GI discomforts.
Dilutes solution concentration
Food and fluids can dilute the concentration of the magnesium citrate solution in the intestines, making it less effective.
Leads to inadequate prep
Overall, eating before or during magnesium citrate prep leads to inadequate bowel cleansing. This often requires repeating or extending the prep to properly cleanse the bowels.
What Foods Should be Avoided?
Here are some examples of solid foods that should be avoided when taking magnesium citrate as a colonoscopy prep:
Meat, poultry, fish
Animal proteins like beef, chicken, pork, eggs, fish and shellfish.
Dairy products
Milk, cheese, yogurt, ice cream, butter, sour cream
Breads, grains
Bread, pasta, oatmeal, rice, quinoa, cereal
Fruits and vegetables
Raw vegetables, cooked vegetables, fruit skins and seeds, salads
Nuts and seeds
Almonds, walnuts, sunflower seeds, flax seeds, chia seeds
Fats and oils
Butter, margarine, vegetable oil, mayonnaise, salad dressing, cream sauce
Sweet treats
Cookies, cake, chocolate, ice cream, pudding
Snack foods
Chips, pretzels, crackers, granola bars
Of course, the most important thing is to follow your doctor’s specific instructions on eating with magnesium citrate prep. But in general, a liquid diet is recommended.
What About Fiber Supplements Like Metamucil?
Fiber supplements such as Metamucil, Benefiber, or Citrucel should be avoided when taking magnesium citrate.
Although fiber helps promote regularity under normal circumstances, the goal of magnesium citrate is to completely empty out the bowels.
The added fiber from supplements can interfere with the cleansing action of the magnesium citrate. Fiber bulks up the stool and could clog the intestines when you need to be cleared out.
Some healthcare providers may recommend stopping fiber supplements 2-3 days before starting magnesium citrate prep to ensure the bowels are emptied.
Can I Drink Alcohol with Magnesium Citrate?
It is not recommended to drink alcohol while taking magnesium citrate as a colonoscopy prep.
Reasons to avoid alcohol include:
- Alcohol can cause dehydration which is already a risk with magnesium citrate due to fluid loss from diarrhea. Dehydration can make side effects like dizziness worse.
- Alcohol irritates the digestive system, potentially worsening cramps, nausea, and vomiting from the magnesium citrate.
- Alcohol delays stomach emptying, which can prolong the action of the magnesium citrate.
- Alcohol can alter electrolyte balances when combined with a laxative like magnesium citrate.
- Alcohol can cause drowsiness or dizziness, making it unsafe to drive to and from your colonoscopy appointment.
For these reasons, it is safest to avoid drinking any alcohol while taking magnesium citrate for bowel prep. Be sure to drink plenty of clear fluids like water, broth, and juice to stay hydrated.
What About Medications?
When it comes to taking medications with magnesium citrate, follow these guidelines:
- Oral medications – Avoid taking other oral medications 1 hour before or after drinking magnesium citrate. This allows maximum absorption of the magnesium citrate solution.
- Timed medications – If you take any medications on a timed schedule, consult your pharmacist or doctor to determine if the schedule should be adjusted with the bowel prep.
- Supplements – Iron supplements, Vitamin C, calcium supplements and other minerals can interact with magnesium citrate absorption. Stop supplements 24-48 hours before taking magnesium citrate.
- Prescriptions – Check with your pharmacist to ensure magnesium citrate won’t interact with your prescription medications like blood pressure pills, opioids, kidney medications, etc.
Be sure your medical team has a full list of your medications to determine any necessary adjustments to take with the magnesium citrate bowel prep.
Tips for Reducing Side Effects
Magnesium citrate can cause unpleasant side effects like nausea, cramping, bloating, and vomiting in some people. Here are some tips to help minimize adverse effects:
Avoid solid foods
Fasting from solid foods before and while taking magnesium citrate can greatly reduce side effects.
Stay hydrated
Drink plenty of clear fluids like water, broth, diluted juice, or electrolyte beverages to prevent dehydration.
Take it chilled
Drink magnesium citrate cold from the refrigerator to make it more palatable and reduce nausea.
Use a straw
Using a straw to drink the solution can help bypass taste receptors and minimize nausea.
Add flavor
Mixing a few ounces of clear juice like lemon, lime, or apple into the solution can help improve the taste.
Take it slowly
Instead of chugging, sip the magnesium citrate solution slowly over the course of 15-30 minutes.
Stay near a restroom
The laxative effect can be sudden. Stay near a toilet until the bowel movements subside.
Let your doctor know if you experience severe reactions like vomiting, weakness, irregular heartbeat, or muscle spasms after taking magnesium citrate.
What If I Accidentally Eat?
If you accidentally eat something solid while taking magnesium citrate as a colon cleanse prep, try not to worry. Here are some tips:
- Drink extra fluids – Have 8-16 oz of water or clear broth if you eat something to help flush your system.
- Wait and see – Monitor whether you continue having bowel movements. You may still clear out adequately.
- Take more prep – You can drink an additional dose of magnesium citrate if bowel movements slow or stop.
- Call your doctor – Let your physician know if you’re concerned the prep may be ineffective.
Having a small snack or meal may just prolong the prep process. But eating a heavy or high fiber meal can interfere with bowel cleansing. Contact your doctor right away if this happens for guidance.
The Day Before Your Colonoscopy
Here are some tips for limiting food intake the day before your colonoscopy after starting magnesium citrate prep:
Breakfast
Avoid solid foods. Stick to clear liquids like water, plain tea, black coffee, or apple juice.
Lunch
Broth, pulp-free juice diluted with water, sports drinks, or popsicles are good options.
Dinner
Have an early light dinner of clear broth soup and juice. Avoid milk, smoothies, or cloudy liquids.
Hydration
Focus on staying hydrated with plenty of approved clear fluids.
Avoid
No solid foods, milk, smoothies, alcohol, or orange juice with pulp after starting prep.
Check with your doctor about eating schedule restrictions the day before your colonoscopy. Follow prep instructions closely for best results.
Can I Drink Coffee?
Drinking black coffee without cream or milk is generally allowed when taking magnesium citrate for colonoscopy prep. However, there are a few things to consider:
- Limit caffeinated coffee to avoid dehydration from the diuretic effect.
- Be sure to drink plenty of other decaffeinated clear fluids like water or juice.
- Avoid adding milk, cream, or whitener which are not clear liquids.
- Restrict coffee to 1-2 cups early in the prep process as it can prolong the action.
- Coffee can worsen dehydration and cause reliance on laxatives. Use in moderation.
Overall, a small amount of black coffee can help make fasting more tolerable. But too much can be counterproductive. Check with your medical team about specific instructions on consuming coffee.
What Can I Eat After Taking Magnesium Citrate?
After completing magnesium citrate bowel prep, follow these general guidelines on what you can eat:
Procedure day
- No solid foods until after your colonoscopy.
- Clear liquids only until 2 hours pre-procedure.
- Fast completely for at least 2 hours before your scheduled time.
Same day after procedure
- Start with clear liquids – water, broth, juice, popsicles, gelatin.
- Progress to bland low-fiber foods if tolerated – toast, rice, noodles, chicken.
- Avoid fried, spicy, dairy, fruits, veggies, nuts, seeds, popcorn.
Next day
- Can resume normal diet if recovered from procedure.
- May still want to avoid raw fruits/veggies and high fiber foods temporarily.
- Drink plenty of fluids as digestive system recovers.
Resume regular foods gradually. Listen to your body and don’t overdo it. Let your doctor know if you have concerns about eating after your colonoscopy.
Conclusion
Taking magnesium citrate on an empty stomach is recommended for proper bowel cleansing before colonoscopy. While solid foods should be avoided, clear liquids are generally allowed. Stay hydrated, follow prep directions closely, and let your doctor know if you have any issues with tolerating the magnesium citrate solution. With the right preparation, your colonoscopy procedure should go smoothly.