What to Buy for Colonoscopy Prep: A Shopping List

Your colonoscopy prep shopping list has three layers: the bowel-preparation solution your doctor prescribed, the food and drinks that keep you comfortable during the restricted-diet phase, and a handful of household supplies that make the whole experience less miserable. Most people focus on the laxative itself and forget everything else until the night before, which leads to a last-minute scramble. Stocking up a few days ahead lets you concentrate on following instructions rather than hunting for ginger ale at 9 p.m.

The Prep Solution Itself

Your gastroenterologist will prescribe (or recommend) a specific bowel-prep product. You do not choose this on your own, but it helps to know what you are picking up so you can grab any extras it requires. The most common class is polyethylene glycol (PEG)-based solutions, which work by drawing water into the intestine and flushing everything out.¹ Some PEG preps come as large-volume jugs you mix with water at home (the classic four-liter variety). Others are low-volume formulas paired with extra clear fluids you drink alongside them. A third category skips PEG entirely and uses sodium sulfate or magnesium citrate combinations, often sold as tablets or smaller liquid doses.

When you pick up the prescription, check whether you also need a mixing container, a flavor packet (some brands include one; others do not), or a specific sports drink to combine with the powder. If the instructions say “mix with 64 ounces of Gatorade,” buy that Gatorade at the same time so it is waiting at home. Avoid anything red, purple, or blue, because those dyes can coat the colon wall and mimic blood or tissue abnormalities during the procedure. Stick to yellow, green, orange, or clear varieties.

What to Eat Before the Clear-Liquid Phase

Most prep instructions include a dietary restriction phase that starts one to three days before the procedure. Traditionally, patients were told to eat nothing but clear liquids for a full day. The evidence has shifted, though. A randomized trial comparing a low-fiber diet to a clear-liquid-only diet found that the low-fiber group actually had better bowel preparation, with adequate cleansing in about 96% of patients versus 89% on clear liquids alone, and participants reported less hunger and discomfort.² A separate controlled trial confirmed that a low-residue diet produced bowel prep quality that was noninferior to strict clear liquids, with similar polyp detection rates and patient tolerance.³

If your doctor’s instructions allow a low-fiber or low-residue diet, here is what to put in your cart for that phase:

Proteins: skinless chicken breast, white fish, eggs, tofu, smooth peanut butter in small amounts.
Starches: white bread, white rice, plain pasta, saltine crackers, low-fiber cereal like corn flakes or Rice Krispies.
Dairy: plain yogurt (no seeds or fruit chunks), mild cheese, milk if you tolerate it.
Cooked vegetables: well-cooked carrots, peeled potatoes, canned green beans. Avoid raw vegetables, corn, broccoli, and anything with visible seeds or skins.

A multicenter trial found that patients given prepackaged low-residue meals had a 94.5% adequate bowel prep rate compared to about 80% among patients who assembled their own low-residue diet, largely because the prepackaged group stuck to the rules more consistently.⁴ The takeaway is not that you need to buy a special kit but that the biggest risk is drifting off-plan. Keep your meals simple and bland during this window, and you will be fine.

Clear Liquids to Stock Up On

Once you transition to clear liquids only, typically the afternoon or evening before the procedure, you need enough variety to stay hydrated and get some calories without feeling completely deprived. “Clear” means you can see through it, not that it has to be colorless. Again, avoid red, purple, and blue dyes.

Fill your cart with a mix of the following:

Broths: chicken broth, beef broth, or vegetable broth. These provide sodium and a savory break from all the sweet drinks. Strain out any solids.
Sports drinks: Gatorade, Pedialyte, or store-brand electrolyte drinks in approved colors. These replace sodium, potassium, and sugar your body is losing.
Juices: apple juice, white grape juice, white cranberry juice. No pulp.
Gelatin: Jell-O or store-brand gelatin in lemon, lime, or orange flavors. Skip anything with fruit pieces.
Popsicles: clear or translucent popsicles in approved colors. These feel like a treat when you are hungry and tired of drinking.
Tea and coffee: black coffee or plain tea are fine for most preps. No cream or milk. Some doctors restrict caffeine, so check your instructions.
Ginger ale or lemon-lime soda: useful both as a clear liquid and to settle your stomach during the prep itself.
Hard candy: lemon drops, butterscotch, or other clear hard candies can help with hunger and the taste between prep doses.

Buy more than you think you need. You will be drinking far more fluid than normal, and variety keeps you from dreading the next sip. Many people find the sweet drinks become cloying after a few hours, so having both broth and juice options prevents flavor fatigue.

Comfort and Bathroom Supplies

The prep works by giving you hours of frequent, watery bowel movements. Your shopping list should reflect that reality:

Wet wipes or flushable wipes: gentler than toilet paper after repeated trips. Some people prefer baby wipes.
Barrier cream: a diaper-rash cream with zinc oxide or plain petroleum jelly applied to the skin around the anus between trips prevents rawness and burning.
Soft toilet paper: if you prefer paper over wipes, buy the softest brand you can find.
A good straw: drinking the prep through a straw positioned toward the back of your tongue can reduce how much you taste it.
Phone charger or reading material: you will be spending time in the bathroom. Be comfortable.

A cooler or pitcher with ice near the bathroom is helpful too. Most PEG solutions taste better very cold. Some patients keep the solution in the refrigerator and pour small glasses as they go rather than having the whole jug warm up on the counter.

Making the Prep Taste Better

The taste and volume of the prep solution are the biggest complaints, and plenty of online advice suggests adding flavor packets to improve things. One clinical trial actually tested this directly, comparing flavored and unflavored PEG solution. The result was that flavor made no significant difference in cleansing success or in patients’ ability to finish the prep.⁵ That does not mean you should skip flavor if it makes the experience more bearable for you, only that adding Crystal Light or lemon juice to the jug is unlikely to be a game-changer for your colon cleanliness. The real strategies that help with tolerability are temperature (chill the solution), pace (drink in steady portions rather than chugging), and using a straw.

Some people swear by chasing each glass of prep with a sip of ginger ale or sucking on a lemon wedge. Hard candy between glasses can also reset your palate. If the prep makes you nauseous, a slow-down break of 15 to 30 minutes usually helps more than pushing through.

Simethicone as an Add-On

One item that often flies under the radar is simethicone, the active ingredient in Gas-X or generic anti-gas tablets. Simethicone breaks up bubbles in the gut, and foam on the colon wall can actually obscure the doctor’s view during the procedure. A randomized trial found that taking simethicone before the colonoscopy significantly reduced bubble scores and led to fewer times the endoscopist had to irrigate during the exam. Patients who took it the morning of the procedure got better results than those who took it only the day before.⁶

Not every prep instruction sheet mentions simethicone, but it is inexpensive, over-the-counter, and has almost no side effects. Ask your doctor whether adding a dose the morning of the exam makes sense. If they agree, toss a box in your cart.

Why Prep Quality Actually Matters

It is tempting to cut corners, drink a little less of the solution, or sneak some food that is not on the approved list. But the whole point of a screening colonoscopy is catching polyps before they turn into cancer, and a poorly prepped colon makes that harder. A meta-analysis found that both intermediate-quality and high-quality bowel preparation had significantly higher adenoma detection rates compared to low-quality preparation, with an absolute difference of about 5 percentage points.⁷ In practical terms, an inadequate prep means the doctor either misses things or asks you to come back and do the whole process again sooner, which nobody wants.

Adequate versus high-quality prep, on the other hand, showed almost no difference in detection rates, so you do not need a “perfect” cleanse. You just need to clear the bar of adequate, which means following the instructions, drinking the full volume, and not eating restricted foods.

Special Considerations for People with Diabetes

If you take diabetes medications, your shopping list needs to include a glucose meter (if you don’t already have one) and fast-acting glucose tablets or juice boxes for treating low blood sugar. The restricted diet combined with your medications creates a real hypoglycemia risk, and the medication adjustments are more involved than most people expect.

Guidelines recommend stopping metformin when the clear-fluid diet begins and resuming it once normal meals restart. GLP-1 receptor agonists follow a similar pattern, though patients on weekly injectable versions should hold the dose if it falls within two days of the procedure. SGLT-2 inhibitors require the longest lead time: they should be stopped three full days before the colonoscopy because their effects persist well beyond the last dose. Sulfonylureas stop the full day before, and insulin doses generally get reduced by roughly half during the clear-liquid phase, with specific adjustments depending on the type of insulin.⁸ A separate review of international guidelines largely agreed on these principles, though recommendations around basal insulin adjustments varied somewhat by diabetes type and timing.⁹

The key shopping-list items here are glucose monitoring supplies, fast-acting sugar sources (glucose tabs, regular soda, juice), and enough approved clear liquids to maintain blood sugar in a safe range. Clear apple juice and sports drinks with sugar, rather than their sugar-free versions, become especially important for people on insulin or sulfonylureas who need some caloric intake during the fasting window. Talk with your prescribing doctor and your gastroenterologist before the prep so you have a written medication plan in hand.

A Note on GLP-1 Medications and Sedation Safety

If you take a GLP-1 receptor agonist like semaglutide (Ozempic, Wegovy) or tirzepatide (Mounjaro, Zepbound) for diabetes or weight management, there is a separate concern beyond blood sugar. These drugs slow stomach emptying, and a study found that about 14% of GLP-1 receptor agonist users had retained food in their stomach at the time of an upper endoscopy, compared to roughly 4% of non-users.¹⁰ Retained stomach contents raise the risk of aspiration, where food enters the airway during sedation.¹¹

Interestingly, the same study found that bowel prep for a same-day colonoscopy actually reduced the odds of retained gastric contents, likely because the large fluid volume and laxative effect helps empty the stomach too. Still, anesthesiologists and gastroenterologists are increasingly asking GLP-1 patients to stop these medications days or even a week before any procedure involving sedation. This is evolving guidance, so bring it up with your doctor early. It may change the timing of your last dose and affect when you start your prep.

Kidney Concerns and Staying Hydrated

Bowel prep solutions have been associated in rare cases with kidney problems and electrolyte disturbances, including a few serious reports over the years.¹² This concern applies mostly to older phosphate-based preps (sodium phosphate solutions), which are no longer widely used for exactly this reason. The PEG-based preps that dominate the market today have a much better safety profile. A study looking at a two-liter PEG solution in patients with and without chronic kidney disease found no significant difference in kidney function before and after the colonoscopy in either group, and no acute kidney injuries occurred.¹³

The practical point for your shopping list: hydration matters. Buy extra electrolyte drinks, extra broth, and extra water. The prep pulls a large volume of fluid through your body, and replacing it aggressively prevents dehydration-related issues like headaches, dizziness, and the electrolyte shifts that occasionally cause trouble. If you have known kidney disease, your doctor may prescribe a specific low-volume prep designed to minimize fluid and electrolyte stress. Do not substitute a different prep product on your own.

The Quick Reference Shopping List

Here is everything in one place, organized by when you will use it:

Prescription prep solution: pick up from the pharmacy, check whether it requires a mixing container or a sports drink.
Low-fiber foods (if allowed): white bread, white rice, eggs, skinless chicken, plain pasta, low-fiber cereal, smooth peanut butter, mild cheese, canned soft vegetables.
Clear liquids: chicken/beef/vegetable broth, sports drinks (yellow, green, orange, or clear), apple juice, white grape juice, gelatin, popsicles, ginger ale, lemon-lime soda, tea, black coffee, hard candy.
Comfort supplies: wet wipes, zinc oxide cream or petroleum jelly, soft toilet paper, straws, a cooler or pitcher for keeping the solution cold.
Optional add-ons: simethicone (Gas-X), lemon wedges for palate cleansing, Crystal Light or similar for flavoring the prep if your instructions allow it.
For people with diabetes: glucose meter and test strips, glucose tablets, regular (not diet) juice or soda for treating lows.

Buy everything at least two to three days before the procedure starts. The day before your colonoscopy will be busy enough without errands. Most of these items are shelf-stable or refrigerator staples, so nothing goes to waste if the appointment gets rescheduled. And if you have leftover broth and Jell-O after the procedure, treat yourself to a proper meal first. You will have earned it.