Can Trimebutine Cause Diarrhea?
No, trimebutine does not typically cause diarrhea; in fact, it is used to treat diarrhea-predominant IBS and has been shown to improve diarrhea symptoms rather than worsen them.
Evidence from Clinical Studies
The available evidence consistently demonstrates that trimebutine reduces diarrhea rather than causing it:
In IBS with diarrhea treatment: Multiple studies show trimebutine effectively treats diarrhea-predominant IBS. A randomized controlled trial found that trimebutine significantly decreased diarrhea scores from 4.13 ± 0.65 to 1.25 ± 0.62 after treatment 1. Another study demonstrated that trimebutine prevented stress-induced and 5-HT-induced diarrhea in animal models 2.
Symptom improvement profile: In a three-part controlled study, trimebutine at 200 mg three times daily effectively controlled multiple IBS symptoms including diarrhea, with no reports of diarrhea as an adverse effect 3. The drug improved both constipation and diarrhea symptoms depending on the patient's presentation 1.
Mechanism of Action
Trimebutine works as a gut motility modulator rather than a secretagogue:
- It acts on peripheral mu, kappa, and delta opioid receptors
- It modulates gastrointestinal peptide release and ion channels
- It regulates both hypermotility and hypomotility states 4
This is fundamentally different from drugs like linaclotide, plecanatide, and tenapanor (guanylate cyclase-C agonists), which do cause diarrhea as their primary adverse effect. These secretagogues increase intestinal fluid secretion, with diarrhea rates of 4.3% for plecanatide versus 1% for placebo 5, and similar rates for linaclotide and tenapanor [@2,3@].
Actual Adverse Effects of Trimebutine
The documented side effects are mild and include:
- Dry mouth (most common)
- Mild thirst
- Constipation (not diarrhea)
- Dizziness
- Nausea
The adverse event rate is low at approximately 22-23%, with no serious adverse events reported [@7,8@].
Clinical Context
You may be confusing trimebutine with secretagogue laxatives used for IBS with constipation (IBS-C), which commonly cause diarrhea as their mechanism of action. Trimebutine has the opposite pharmacological profile—it normalizes motility in both directions and has been specifically studied for its anti-diarrheal properties in IBS-D patients.