Trulance (plecanatide) is a prescription medication used to treat two forms of chronic constipation in adults: chronic idiopathic constipation (CIC) and irritable bowel syndrome with constipation (IBS-C). The FDA first approved it for chronic idiopathic constipation in January 2017, then expanded its approval to cover IBS-C the following year. It’s taken as a once-daily tablet and works by increasing fluid in the intestines to help stool pass more easily.
The Two Conditions Trulance Treats
Chronic idiopathic constipation is ongoing constipation with no identifiable underlying cause. “Idiopathic” simply means doctors can’t point to another condition, medication, or structural problem causing it. People with CIC typically have fewer than three bowel movements per week, and the ones they do have often involve straining, hard stools, or a feeling of incomplete emptying. This isn’t the occasional constipation that comes with travel or a change in diet. It’s persistent, lasting months or longer.
IBS-C shares many of those same constipation symptoms but adds abdominal pain into the mix. The pain is directly tied to bowel habits, often improving or worsening around the time of a bowel movement. IBS-C is a subtype of irritable bowel syndrome where constipation is the dominant pattern rather than diarrhea or an alternating mix of both. Trulance is approved for the constipation-predominant form only.
How Trulance Works in the Gut
Trulance mimics a natural hormone called uroguanylin that your body already produces in the intestines. It binds to a receptor called GC-C on the inner surface of the intestinal lining. When that receptor is activated, it triggers a chain reaction that causes cells to release chloride and bicarbonate ions into the intestinal space. Water follows those ions, which increases the amount of fluid in the gut. More fluid softens stool and speeds up its movement through the intestines.
Because Trulance acts locally on the intestinal lining rather than being absorbed into the bloodstream in significant amounts, its effects are largely confined to the digestive tract. This is part of why its side effect profile is mostly gastrointestinal rather than systemic.
What to Expect When Starting Treatment
In clinical trials, patients saw improvements in bowel movement frequency as early as the first week of treatment. Those improvements held steady through the full 12-week study period. For chronic idiopathic constipation specifically, about 21% of patients taking Trulance achieved the primary goal of three or more complete spontaneous bowel movements per week on a durable basis, compared to roughly 10% of patients taking a placebo. That gap may sound modest in percentage terms, but for someone who’s been struggling with chronic constipation, doubling the response rate over placebo represents a meaningful difference.
Trulance is taken once daily, with or without food. The standard dose is one 3 mg tablet. It can also be crushed and mixed with applesauce or water for people who have difficulty swallowing pills.
Common Side Effects
The most frequently reported side effect is mild diarrhea, which makes sense given the drug’s mechanism of increasing intestinal fluid. Other side effects seen in clinical trials include nausea, gas, bloating or abdominal tenderness, dizziness, upper respiratory infections like the common cold, and urinary tract infections. Most of these are mild.
Severe diarrhea is rare but possible. If it occurs, it can lead to dehydration, particularly in older adults or people who don’t compensate by drinking enough fluids. Elevated liver enzymes have also been reported in rare cases.
Who Should Not Take Trulance
Trulance carries a boxed warning, the FDA’s most serious safety label, regarding use in young children. It is contraindicated in children under 6 years of age. In animal studies, young mice given the drug experienced dangerous levels of fluid secretion into the intestines, leading to severe dehydration and death in some cases within 24 hours. The reason young animals are more vulnerable is that their intestines have higher concentrations of the GC-C receptor that Trulance activates. Children under 6 are thought to share this heightened sensitivity. The FDA also recommends avoiding Trulance in patients aged 6 through 17, though the restriction is strongest for those under 6.
People with known or suspected mechanical bowel obstruction should also not take Trulance, since increasing fluid and motility in a blocked intestine could cause serious complications.
How Trulance Compares to Other Options
Trulance belongs to the same drug class as linaclotide (Linzess), another GC-C agonist approved for the same two conditions. Both work through similar biological pathways, and both carry the same pediatric boxed warning. The choice between them often comes down to individual response, side effect tolerance, and insurance coverage. Trulance was designed to more closely mimic the body’s natural uroguanylin hormone, though both medications have demonstrated effectiveness in clinical trials.
For people with milder symptoms, lifestyle changes like increased fiber intake, adequate hydration, and regular physical activity remain the first line of approach. Over-the-counter osmotic laxatives are another step before prescription options. Trulance is typically considered when those measures haven’t provided enough relief and constipation is significantly affecting quality of life.