Trulance (plecanatide) is a prescription medication that relieves constipation, but it works differently from the laxatives you’d find on a drugstore shelf. It belongs to a drug class called guanylate cyclase-C agonists, which mimic a natural hormone in your gut to increase fluid secretion and move waste through your intestines. Cleveland Clinic does categorize it as a prescription laxative, but its mechanism, intended use, and regulatory status set it apart from over-the-counter options like MiraLAX or Dulcolax.
How Trulance Differs From OTC Laxatives
Over-the-counter laxatives generally fall into a few categories. Osmotic laxatives like MiraLAX draw water into the colon to soften stool. Stimulant laxatives like Dulcolax trigger contractions in the intestinal muscles to push things along. Both are designed for occasional or short-term constipation.
Trulance takes a fundamentally different approach. It mimics uroguanylin, a hormone your body naturally produces to regulate fluid balance in the intestines. When Trulance binds to receptors on the intestinal lining, it triggers a chain reaction: cells release chloride and bicarbonate ions into the intestinal space, which pulls water in after them. At the same time, it blocks the reabsorption of sodium, which further prevents your intestines from pulling fluid back out. The net effect is softer, more hydrated stool that moves more easily.
This targeted mechanism is why Trulance requires a prescription. It’s not meant for the occasional bout of constipation that a fiber supplement or osmotic laxative could handle. It’s FDA-approved specifically for two chronic conditions in adults: chronic idiopathic constipation (CIC), which is long-term constipation with no identifiable underlying cause, and irritable bowel syndrome with constipation (IBS-C).
How Well It Works
In clinical trials, people taking Trulance had about 1.1 more complete spontaneous bowel movements per week than those on placebo. That may sound modest, but for someone with chronic constipation who might have only one or two complete bowel movements a week, it represents a meaningful improvement. Results showed up as early as the first week of treatment and held steady through 12 weeks.
“Complete spontaneous” is an important distinction here. It doesn’t just mean having a bowel movement. It means having one without the help of a rescue laxative and feeling like you’ve actually emptied your bowels afterward, which is a common frustration for people with CIC or IBS-C.
What to Expect With Side Effects
The most common side effect is diarrhea, which makes sense given that the drug works by increasing fluid in the intestines. In clinical trials for chronic constipation, about 5% of people taking Trulance experienced diarrhea compared to 1% on placebo. For IBS-C trials, the rate was 4.3% versus 1%. So while diarrhea is the primary concern, the vast majority of people in studies didn’t experience it.
Trulance carries a serious safety warning for children. It is contraindicated in children under 6 years old because their intestines have higher concentrations of the receptors Trulance targets, which could cause severe diarrhea and dangerous dehydration. In animal studies, young mice given the drug experienced fatal dehydration within 24 hours. The medication should also be avoided in anyone between 6 and 17, as safety and effectiveness have not been established in that age group. If you have young children at home, keeping Trulance stored safely out of reach matters, since accidental ingestion could be dangerous.
Where Trulance Fits in Constipation Treatment
Most people with constipation start with lifestyle changes (more fiber, more water, more movement) and move to over-the-counter options if those aren’t enough. Trulance typically enters the picture when OTC laxatives haven’t provided adequate relief, or when constipation is chronic enough to warrant a different approach. It’s taken once daily and is designed for ongoing use rather than as-needed dosing.
Another drug in the same class, linaclotide (Linzess), works through a very similar mechanism. Both tap into the same natural hormone pathway that regulates intestinal fluid. The choice between them often comes down to individual response, insurance coverage, and your doctor’s preference. Beyond relieving constipation, research suggests these guanylate cyclase-C agonists may also help reduce the abdominal pain that often accompanies IBS-C, because the same signaling pathway that controls fluid secretion also influences pain signaling in the gut.
So while calling Trulance a laxative isn’t technically wrong, it undersells what the drug does. It’s a targeted, prescription-level treatment for chronic conditions that ordinary laxatives can’t adequately manage.