Prescription ·Strong evidence ·Reviewed May 2026
Dicyclomine is an anticholinergic antispasmodic used for functional bowel and irritable bowel syndrome with painful intestinal cramping. It reduces gastrointestinal smooth muscle spasm but can cause clinically important anticholinergic adverse effects, especially in infants, older adults, glaucoma, urinary retention, and obstructive gastrointestinal disease.
The bottom line
Evidence rating strong. Most-documented uses: short-term relief of irritable bowel syndrome cramping, reduction of functional gastrointestinal smooth muscle spasm, adjunctive symptom control for abdominal pain related to bowel spasm. 3 sources indexed (2008–2026), with 4 interaction records on file.
Core mechanism
Dicyclomine antagonizes muscarinic acetylcholine receptors and also has a direct relaxant effect on gastrointestinal smooth muscle. Reduced parasympathetic tone decreases intestinal motility and spasm, which can improve cramping pain in irritable bowel syndrome. The same antimuscarinic activity can impair sweating, accommodation, bladder emptying, bowel transit, and cognition, explaining heat illness, blurred vision, constipation, urinary retention, tachycardia, confusion, and delirium risks.2,3
Oral doses may be taken with or without food. Separate from bulky fiber if symptoms or absorption concerns occur, and avoid alcohol or other sedatives when drowsiness is present.
Anticholinergic slowing of gastrointestinal transit may increase irritation risk from solid oral potassium products.
Recommendation: Use potassium only as directed by a clinician; liquid or divided formulations may be preferred when anticholinergic therapy is necessary.
Melatonin may add to dicyclomine-related drowsiness, dizziness, and impaired alertness.
Recommendation: Use low doses cautiously and avoid driving or hazardous tasks until individual response is known.
L-theanine can be calming and may compound dicyclomine-associated sedation or dizziness.
Recommendation: Monitor for sleepiness and avoid combining with other sedatives unless supervised.
Bulking fiber can delay absorption of oral drugs and dicyclomine can worsen constipation in some patients.
Recommendation: Separate psyllium and dicyclomine by at least 2 hours and increase fluids if fiber is used.
Numbered references. Citations throughout the page link here.
Antispasmodic therapy showed benefit for global IBS symptoms, though adverse effects and study quality vary.
Guideline emphasizes symptom-directed IBS therapy and careful adverse-effect consideration with antispasmodics.
Labeling lists IBS indication, adult dosing, contraindications including infants, glaucoma, myasthenia gravis, obstruction, breastfeeding, and warnings for heat prostration and delirium.
This page is educational. Do not start, stop, or change a supplement or medication based on it without checking with a qualified healthcare professional.
Use this with your stack
Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.
NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.
