Sutab is a prescription tablet used to clean out your colon before a colonoscopy. It’s FDA-approved for adults and offers a pill-based alternative to the large-volume liquid prep drinks that many patients dread. The active ingredients are sodium sulfate, magnesium sulfate, and potassium chloride, all of which draw water into your intestines to flush them out.
How Sutab Works
The salts in Sutab are osmotic laxatives, meaning they pull water from your body into your bowel. This creates a flushing effect that clears stool and debris so your doctor can get a clear view of the colon lining during the procedure. It’s the same basic principle behind liquid bowel preps, but delivered as tablets you swallow with water instead of drinking a flavored solution.
How Well It Works
In two FDA-reviewed clinical trials, 92% of patients who used Sutab achieved a successful bowel preparation, defined as “good” or “excellent” cleansing with clear visualization of the entire colon lining. That matched or slightly outperformed the liquid preps it was tested against: 89% success in one trial and 88% in the other. For most people, the tablet format doesn’t come at the cost of effectiveness.
What the Prep Process Looks Like
Sutab comes as a kit with two bottles, each containing 12 tablets. You take it as a split dose: the first 12 tablets the evening before your colonoscopy (typically starting around 4 p.m.), and the second 12 tablets several hours before the procedure itself. The exact timing of the second dose depends on your scheduled arrival time. For a noon appointment, for example, you’d start the second dose around 11 p.m. the night before.
Each dose follows the same routine. You fill the included cup with 16 ounces of cool water, swallow all 12 tablets with sips from that cup, then finish whatever water remains. Over the next 30 minutes, you drink a second 16-ounce cup of water, followed by a third. That means each dose involves about 48 ounces of water on its own.
Hydration is critical. Beyond the water you drink with the tablets, you should aim for at least 12 additional servings (8 to 10 ounces each) of clear liquids throughout the prep period. This replaces fluids lost during the bowel-clearing process and helps prevent dehydration.
Common Side Effects
Bowel prep is inherently uncomfortable, and Sutab is no exception. In clinical trials involving 941 adults, the most commonly reported side effects were:
- Nausea: reported by about half of patients (48% to 52% across the two studies)
- Bloating: reported by roughly a third (29% to 34%)
- Stomach cramping: reported by 16% to 23%
Most of these symptoms were mild to moderate and resolved before the colonoscopy. Vomiting can also occur. The large volume of water you need to drink alongside the tablets contributes to the bloating and nausea, so pacing yourself through each cup helps.
Who Should Not Take Sutab
Sutab is not safe for everyone. It is contraindicated if you have:
- Bowel obstruction or ileus: any blockage that prevents normal movement through the intestines
- Bowel perforation: a hole or tear in the intestinal wall
- Toxic colitis or toxic megacolon: severe inflammation and dilation of the colon
- Gastric retention: a condition where the stomach cannot empty properly
- Allergy to any ingredient in the tablets
Because Sutab contains salts that shift your body’s electrolyte levels, people with kidney problems or heart conditions may need extra monitoring or a different prep altogether. Your prescribing doctor will review your medical history before choosing Sutab over other options.
Why Some People Prefer Tablets
The main appeal of Sutab is simple: you don’t have to drink a large jug of flavored solution. Traditional liquid preps require consuming one to four liters of fluid that many people find unpleasant in taste and texture. For patients who have struggled with liquid preps in the past, gagged on the flavor, or been unable to finish the full volume, a tablet option can make the difference between completing the prep and showing up inadequately prepared. You still drink a significant amount of water with Sutab, but plain water is generally easier to tolerate than a salty or sweet prep solution.