Vomiting after taking Sutab is common and doesn’t automatically mean your colonoscopy needs to be cancelled. In clinical trials, between 16% and 23% of patients reported vomiting during their Sutab prep. What you should do next depends on how soon you vomited, how much you threw up, and whether you can keep going.
What to Do Right Away
If you vomit shortly after swallowing your tablets or drinking the required water, stop for 30 minutes. Rinse your mouth out and let your stomach settle. Once the nausea passes, resume drinking the water that goes with your dose. The official Sutab instructions say that if you experience nausea, bloating, or cramping, you should pause or slow down the rate of drinking water until the symptoms fade.
Drinking large volumes of water quickly is often the trigger. Sutab requires you to drink 16 ounces of water with each set of 12 tablets, then another 32 ounces over the next hour. That’s a lot of liquid in a short window. Slowing down can make a real difference. Try sipping steadily rather than gulping, and give yourself a few extra minutes between glasses if needed.
Whether Your Prep Still Worked
The key question is whether enough of the medication stayed in your system to do its job. Sutab works by pulling water into your intestines through its active salts, which triggers the flushing effect. If you kept the tablets down for 20 to 30 minutes before vomiting, a meaningful portion may have already moved out of your stomach. If you vomited almost immediately after swallowing the tablets, less of the dose was likely absorbed.
There’s no exact cutoff published for how long Sutab needs to stay down, so the best indicator is what’s happening on the other end. A successful prep produces bowel movements that are liquid, yellow, and clear enough that you can see the bottom of the toilet bowl. Small flecks of material and a yellow tint are normal (that’s just bile) and won’t interfere with the procedure. If your stools are still solid or opaque brown, the prep hasn’t done enough.
Should You Still Go to Your Colonoscopy?
Even if you couldn’t keep down every last tablet or ounce of water, you should generally still show up for your scheduled procedure. Drink as much of the remaining prep as you can tolerate, and let your doctor’s office know what happened. Many patients who lose part of their prep still end up clean enough for a successful colonoscopy. Your gastroenterologist can assess your colon once the scope is in and decide whether the view is adequate.
If your bowel movements never progressed to clear liquid, call your doctor’s office before heading in. They may give you additional instructions, reschedule, or ask you to come in anyway and evaluate from there. Calling ahead saves everyone time and lets the team adjust.
When Vomiting Becomes a Bigger Concern
Mild nausea and even a single episode of vomiting are expected side effects. But certain situations call for a prompt phone call to your doctor:
- Severe or persistent vomiting lasting more than two hours, or vomiting that prevents you from keeping down any water at all.
- Signs of dehydration such as dizziness, very dark urine, rapid heartbeat, or feeling faint.
- Vomiting blood or noticing excessive blood in the toilet.
- Abnormal heartbeats or seizures, which are rare but require immediate attention.
Sutab contains sodium sulfate, magnesium sulfate, and potassium chloride. These salts shift your body’s electrolyte balance temporarily. If prolonged vomiting compounds the fluid loss already caused by the prep itself, dehydration and electrolyte imbalances become a real risk. Your doctor may want to check bloodwork after the colonoscopy if significant vomiting occurred.
Tips to Reduce Nausea With the Second Dose
Sutab is a split-dose prep: 12 tablets the evening before your procedure (usually starting around 4 p.m.) and another 12 tablets later that night or early the next morning, depending on your appointment time. If you had trouble with the first dose, a few adjustments can help the second go more smoothly.
Chill the water you’re drinking. Cold water is easier on a queasy stomach than room-temperature water. Space out the tablets if your doctor’s timing allows it, swallowing a few at a time with sips rather than taking all 12 in rapid succession. Keep moving gently between glasses: light walking can help settle your stomach and encourage the prep to work. Avoid lying flat, which can worsen nausea and slow gastric emptying.
If nausea was severe with the first dose, call your doctor’s office before starting the second. They may suggest taking an anti-nausea medication beforehand or adjusting your water intake schedule. Having a plan in place is better than white-knuckling through a repeat episode.
How to Judge Your Prep Quality
Regardless of whether you vomited, the ultimate measure of a successful prep is what your stool looks like by the time you’re done. Here’s a simple guide:
- Clear yellow liquid: You’re well-prepped. This is the goal.
- Yellow liquid with a few small flecks: Still fine. The flecks and color won’t block your doctor’s view.
- Cloudy brown or orange liquid: Borderline. Let your doctor know.
- Still passing solid or semi-solid stool: The prep is incomplete. Call your doctor’s office for instructions before your appointment.
You need to finish all 48 ounces of the required water at least four hours before your colonoscopy. Even if you’re feeling done with liquids, that water is part of the medication’s mechanism. Skipping it reduces the prep’s effectiveness and increases your risk of dehydration.