ד״ר איל שחרגסטרואנטרולוגיה ומחלות כבד

Printable instructions — Meroken. Another preparation? MoviPrep · Pico-Salax (Picolax)
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Printable instructions · Dr. Eyal Shachar, Gastroenterologist

Colonoscopy preparation with Meroken

My exam:

Date Time

The three most important instructions

  1. After the second dose, keep drinking a glass of clear liquid every 30 minutes, until 3 hours before the exam.
  2. Do not eat or drink anything, including water, starting 3 hours before the exam.
  3. You must come with an escort. Do not drive for 8 hours after the exam.

Timeline — tick ✓ when done

  • 1 week beforeStop iron, bismuth (such as Kalbeten) and charcoal. Blood thinners — do not stop them on your own: check with your family doctor or treating gastroenterologist. When to stop each medicine — see the leaflet “Blood thinners before colonoscopy” on the website (Hebrew). Aspirin and blood-pressure medicines — continue as usual.
  • 5 days beforeOnly if you have constipation: a laxative (Laxadin, Pegalax or Normalax), in addition to the preparation.
  • 3 days beforeLow-fiber diet — see the next page. SGLT2 medicines for diabetes (Forxiga, Jardiance, Steglatro) — stop today: risk of acidosis.
  • 24 hours beforeStop eating completely. Clear liquids only — and drink plenty throughout the day.
  • The preparationFollow the table below — according to the time of your exam.
  • Morning of the examRegular medicines (e.g. for blood pressure) — as usual, with a little water, up to 3 hours before the exam. Insulin, diabetes medicines and blood thinners — only as you were instructed.
  • The examArrive 15 minutes early, with an escort, your ID card, your health fund card and the consent form (you sign it at the unit).

The preparation: Meroken

  • Fill the bottle with water up to the 3-liter line and mix until fully dissolved. Add nothing to it — it is already lemon-flavored.
  • Keep it in the fridge. Drink a glass (about 240 ml) every 10 minutes.
Morning exam (07:00–10:59)Exam at 11:00–15:59Exam from 16:00
First dose2 liters of Meroken, followed by at least 2 glasses of clear liquidDay before, at 17:00Day before, at 22:00Exam day, 10 hours beforeMy time:
Second dose1 liter of Meroken and 1 liter of water, then a glass of clear liquid every 30 minutesDay before, after 22:00Exam morning, 5 hours beforeMy time: Exam day, 5 hours beforeMy time:
Nothing to eat or drink, including waterFrom this point until the exam, do not drink anything3 hours before the examMy time:

Exam between 14:00 and 15:59? You can also drink both doses on the morning of the exam. Details on the website, in the question “Preparation on the day of the exam” (in Hebrew) — and discuss this with your treating doctor.

Tell your doctor in advance if you have or take:

  • Blood thinners (Coumadin, Eliquis, Xarelto, Pradaxa, Clexane, Plavix) — check with your family doctor or treating gastroenterologist at least one week before. Do not stop them on your own
  • Diabetes: insulin or tablets
  • Heart or kidney failure, or a fluid restriction
  • Pacemaker, defibrillator or artificial heart valve
  • Allergy to medicines or latex · Sleep apnea (CPAP) or severe obesity (BMI 40 or higher)
  • Medicines from the GLP-1 family, by injection or tablet: Ozempic, Wegovy, Saxenda, Mounjaro, and also Trulicity, Rybelsus (tablet) and pens that combine GLP-1 with insulin (Xultophy, Soliqua). Not sure? Report any weekly injection and any medicine for diabetes or weight loss

What is a colonoscopy, and what are the risks?

A thin, flexible tube with a camera at its tip is passed through the anus, and the doctor examines the lining of the large bowel (colon). If needed, biopsies are taken, polyps are removed or bleeding is stopped. The exam is usually done under sedation and takes about half an hour. Afterwards you stay under observation for about an hour, and then you can eat and drink as usual. During and after the exam you may feel some abdominal discomfort and bloating.

  • As with any invasive procedure, there is a risk of complications: bleeding, or a tear (perforation) in the bowel wall. They are uncommon, but may require hospital admission, further treatment and sometimes surgery.
  • The sedation drugs may rarely cause breathing or heart problems — mainly in people with heart or lung disease — or an allergic reaction.
  • Even during a well-performed examination, some lesions may be missed. The chance of finding them depends greatly on the quality of the bowel preparation.
  • Complications are uncommon. If the exam is recommended, your doctor weighs its benefit against the risks, alternatives and the consequences of delay. You will get an explanation and can ask questions before signing the consent form; please read it in advance.

3 days before: low-fiber diet

✓ Allowed

  • White bread, pita made from white flour
  • Pasta, white rice
  • Potatoes without the skin
  • Chicken, turkey, fish, tuna, eggs
  • Chicken soup
  • Dairy products without fruit, tahini

✗ Not allowed

  • Fruit and vegetables
  • Legumes: beans, chickpeas, peas, lentils, fava beans, corn
  • Whole-grain bread, oats, breakfast cereals, granola, bran
  • Nuts

24 hours before: clear liquids only

Clear liquid = completely transparent; you can see through it.

✓ Allowed

  • Water
  • Tea, without milk
  • Strained juice with no fruit pulp, such as clear apple juice
  • Clear strained broth: no vegetables, no noodles, no fat
  • Clear isotonic drink

✗ Not allowed

  • Milk and dairy products, including plant-based milk
  • Coffee, including black coffee
  • Cloudy juice, such as orange drink (“Tapuzina”)
  • Red or purple liquids

How do you know the preparation has worked?

  1. Dark brownNot ready
  2. Medium brownNot ready
  3. Cloudy orangeKeep drinking
  4. Cloudy yellowKeep drinking
  5. Light yellow, transparent✓ OK
  6. Clear, transparent✓ Ready

Even if your stools are already clear — drink the second dose. You may keep drinking clear liquids until 3 hours before the exam.

Something went wrong? Full explanations on the website

Vomited, missed a dose, no bowel movements, or ate something by mistake — the answers are on the questions page, in the chapter “Something went wrong”, with videos and more than 40 questions and answers (in Hebrew): shachar-gastro.co.il/faq/colonoscopy-prep. For non-urgent questions, call the endoscopy unit where your exam was booked. Still passing brown stool on the morning of the exam? Come to the exam and tell the staff right away. The detailed explanations on the website are in Hebrew. If you cannot read them, ask the endoscopy unit for written instructions in a language you understand.

Go immediately to an urgent care center or an emergency department if you have:

  • Severe abdominal pain, or pain that keeps getting worse — especially with a swollen abdomen
  • Repeated vomiting that prevents you from drinking
  • Severe dizziness, confusion or fainting
  • Shortness of breath, chest pain or an allergic reaction
  • No bowel movements at all after the preparation, together with abdominal pain, a swollen abdomen or vomiting
  • Significant bleeding

General instructions that do not replace personal medical advice. If the endoscopy unit gave you different instructions — follow them.

ד״ר איל שחר — גסטרואנטרולוגיה בגובה העיניים · https://shachar-gastro.co.il · מידע להסבר ולידע כללי בלבד. אינו מהווה ייעוץ רפואי ואינו תחליף לבדיקה אצל רופא.