GoLYTELY is a prescription bowel prep solution you mix into one gallon of water and drink in two separate sessions, typically starting the evening before your colonoscopy. The process takes planning, but the steps are straightforward once you know the timeline, the diet restrictions, and a few tricks to make the taste more bearable.
How to Mix the Solution
You’ll receive a packet of powder that needs to be dissolved in exactly one gallon of lukewarm water. Use a food-grade container that holds at least one gallon. Cut open the packet, pour the entire contents into the container, and add lukewarm water (not hot, not cold) to the one-gallon mark. Lukewarm water helps the powder dissolve fully. Once it’s mixed, put it in the refrigerator. The solution tastes noticeably better cold.
What to Eat the Day Before
You’ll switch to a clear-liquid-only diet for the full day before your procedure. “Clear liquids” doesn’t just mean water. You can have tea (no creamer), coffee without creamer in the morning only, apple juice, white grape juice, white cranberry juice, clear chicken or beef broth, sports drinks, gelatin, popsicles, gummy bears, hard candy, and flavored waters.
The critical rule: nothing red, blue, or purple. These dyes can coat the lining of your colon and look like blood or abnormal tissue during the colonoscopy. So no red sports drinks, no blue gelatin, no purple popsicles. Also avoid all dairy products and any juice with pulp.
The Split-Dose Drinking Schedule
Most doctors now recommend a split-dose schedule, where you drink half the gallon the evening before and the other half the morning of your procedure. This approach is easier on your stomach and produces a cleaner prep than drinking the entire gallon in one sitting.
Evening before (starting around 5 p.m.): Drink half the container over about two hours. Pour yourself an 8-ounce glass every 10 to 15 minutes until you’ve finished half the jug.
Morning of the procedure: Start drinking the remaining half about four hours before you need to leave for your appointment. Same pace: one 8-ounce glass every 10 to 15 minutes until the jug is empty.
That 10-to-15-minute rhythm matters. Drinking faster can overwhelm your stomach and cause vomiting. Drinking slower can drag out the process and leave you with an incomplete prep.
What Happens After You Start Drinking
Expect your first bowel movement within one to two hours of starting the solution. Early on, stools will look normal, then quickly become loose and watery. Over the next several hours, the output gets progressively lighter and more liquid. By the time you finish the second dose the next morning, your stool should look like pale yellow or clear liquid with no solid pieces. That clarity is the goal. If what’s coming out still looks brown or has chunks, your colon isn’t clean enough for the doctor to get a good view during the procedure.
You’ll be making frequent, urgent trips to the bathroom. Plan to stay home and stay close to a toilet from the moment you start drinking. Many people find it helpful to set up near the bathroom with something to watch or read.
How to Make It Easier to Drink
GoLYTELY has a salty, slightly chemical taste that most people find unpleasant. A few adjustments can make a real difference:
- Drink it cold. Chilling the solution in the fridge significantly improves the taste. Some people even put it in the freezer briefly to get it extra cold without freezing it.
- Use a straw. Drinking through a straw bypasses some of the taste buds on your tongue.
- Add a flavor packet. If your pharmacy dispenses the unflavored version, you can add Crystal Light pitcher packs in lemonade, sweet tea, or orange flavor. You’ll need two packets per gallon. Don’t use red, blue, or purple flavors.
- Suck on hard candy between glasses. A lemon drop or ginger candy (no red, blue, or purple) can help reset your palate between rounds.
Dealing with Nausea and Bloating
Nausea and bloating are the most common complaints during prep. If you start feeling nauseous, slow down. Take a 15-to-30-minute break before your next glass. Walking around for a few minutes can help move the liquid through your system and relieve that overfull feeling. If bloating gets uncomfortable, pause until it eases, then resume at the same 8-ounce pace.
Vomiting can happen if you drink too fast or if nausea builds without a break. The key is steady, measured drinking rather than trying to gulp it down and get it over with.
Skin Care and Comfort
Hours of watery bowel movements can irritate the skin around the anus. Use soft toilet paper or, even better, unscented baby wipes. Applying a barrier cream or petroleum jelly to the area before you start drinking can prevent soreness. Some people keep a package of medicated wipes (the kind sold for hemorrhoids) on hand for relief if irritation develops.
How to Know Your Prep Worked
Your prep is successful when what’s coming out of you looks like clear or light yellow liquid, similar to urine, with no solid material. Doctors evaluate colon cleanliness on a formal scale during the procedure, and a poorly prepped colon can mean the colonoscopy needs to be repeated. The cleaner your colon, the better your doctor can spot polyps or other abnormalities. Finishing every last glass of the solution, even when you feel like you’re done, is the single most important thing you can do to avoid a repeat procedure.