Dicyclomine: Uses, How It Works, and Safety Information

Overview

Dicyclomine is a prescription medication used to treat symptoms of irritable bowel syndrome (IBS), particularly abdominal cramping and spasms. It is sold under the brand name Bentyl and is also available in generic form.

As an anticholinergic and antispasmodic medication, dicyclomine works by relaxing the smooth muscle in the gastrointestinal tract, reducing painful cramping and spasms associated with IBS. Unlike loperamide which slows intestinal transit, dicyclomine specifically targets muscle spasms without directly affecting stool consistency or frequency.

How Dicyclomine Works

Dicyclomine belongs to a class of medications called anticholinergics (also known as antimuscarinics). It works by:

Blocking acetylcholine receptors in the smooth muscle of the gastrointestinal tract
Relaxing intestinal smooth muscle to reduce spasms and cramping
Decreasing excessive intestinal motility during spasmodic episodes
Reducing pain signals associated with intestinal muscle contractions

By blocking the action of acetylcholine, dicyclomine prevents the excessive muscle contractions that cause the cramping pain characteristic of IBS.

Common Uses

Dicyclomine is FDA-approved for:

Irritable Bowel Syndrome (IBS):

Abdominal cramping and pain
Intestinal spasms
Discomfort associated with altered bowel function

Dicyclomine treats the spasmodic component of IBS symptoms. It does not treat:

Diarrhea directly (though reducing spasms may help)
Constipation
The underlying cause of IBS
Other gastrointestinal conditions

Forms Available

Dicyclomine is available in several forms:

Oral capsules: 10 mg
Oral tablets: 20 mg
Oral syrup/solution: 10 mg per 5 mL
Injectable solution: 10 mg/mL (for intramuscular use only, typically in medical settings)

The oral forms are most commonly used for outpatient treatment of IBS symptoms.

When NOT to Use Dicyclomine

Dicyclomine should not be used in certain situations:

Do not use if you have:

Obstructive diseases of the gastrointestinal tract
Severe ulcerative colitis or toxic megacolon
Reflux esophagitis
Unstable cardiovascular status in acute hemorrhage
Glaucoma (narrow-angle)
Myasthenia gravis
Obstructive uropathy (urinary obstruction)
Known hypersensitivity to dicyclomine

Important: Dicyclomine is contraindicated in infants younger than 6 months due to serious adverse reactions including seizures, breathing difficulties, and death reported in this age group.

Who Should Avoid or Use Caution

Certain individuals should not use dicyclomine or should consult a healthcare provider first:

Older adults: More susceptible to anticholinergic side effects including confusion, sedation, and heat intolerance
People with autonomic neuropathy
Those with liver or kidney disease
Individuals with hiatal hernia associated with reflux esophagitis
People with coronary heart disease, congestive heart failure, or cardiac arrhythmias
Those with hypertension
Individuals with hyperthyroidism
People with prostatic hypertrophy (enlarged prostate)
Those in hot environments: Anticholinergics reduce sweating and increase heat stroke risk

Prescription Status

Unlike many OTC digestive medications, dicyclomine requires a prescription in the United States. This is because:

It has significant anticholinergic side effects requiring medical monitoring
Proper diagnosis of IBS should be made before treatment
It has important contraindications and drug interactions
Dosing requires medical guidance

Effectiveness

According to clinical evidence and FDA-approved labeling, dicyclomine is effective at:

Reducing abdominal cramping associated with IBS
Decreasing intestinal spasms
Providing relief from spasm-related pain

However, it is important to understand that:

Dicyclomine treats symptoms, not the underlying cause of IBS
It works best for the cramping/spasmodic component of IBS
Individual responses vary
It may not help all IBS symptoms (such as bloating or altered stool patterns)
It is typically used as part of a comprehensive IBS management approach

Duration of Use

Dicyclomine may be used:

Short-term:

During IBS flare-ups
For acute symptom management
As needed for cramping episodes

Longer-term:

Under ongoing medical supervision
With regular evaluation of continued need
With monitoring for side effects

The decision regarding duration of use should be made with a healthcare provider based on symptom severity, response to treatment, and presence of side effects.

Comparison with Other IBS Treatments

Dicyclomine addresses the spasmodic component of IBS. Other approaches include:

Loperamide: For diarrhea-predominant IBS, slows intestinal transit
Fiber supplements: For constipation-predominant IBS
Peppermint oil: Natural antispasmodic with some evidence for IBS
Prescription medications: Various options for specific IBS subtypes
Dietary modifications: Low-FODMAP diet and trigger avoidance
Probiotics: For overall gut health

The best approach depends on the predominant symptoms and individual response to treatment.

Safety During Pregnancy and Breastfeeding

Pregnancy: Dicyclomine is classified as FDA Pregnancy Category B based on animal studies. However, human data are limited. Use during pregnancy should only occur if clearly needed and the potential benefit justifies the potential risk.

Breastfeeding: Dicyclomine is excreted in human milk. According to FDA labeling, it may reduce milk production and has been associated with respiratory symptoms in nursing infants. The decision to use dicyclomine while breastfeeding should weigh the benefits against potential risks to the infant.

Important Safety Information

Anticholinergic effects: Dicyclomine can cause typical anticholinergic side effects including dry mouth, blurred vision, urinary retention, and constipation. These effects may be more pronounced in older adults.

Heat exposure: Dicyclomine can reduce sweating, increasing the risk of heat stroke during exercise or in hot environments.

Driving and operating machinery: Dicyclomine may cause drowsiness, dizziness, or blurred vision. Use caution until you know how it affects you.

Alcohol: May enhance the sedative effects of dicyclomine.

When to See a Healthcare Provider

Seek medical attention if:

IBS symptoms persist or worsen despite treatment
You develop severe abdominal pain or distension
You experience significant anticholinergic side effects
You develop urinary retention
Vision changes occur
You experience rapid heartbeat or palpitations
Signs of heat stroke appear during hot weather
You develop confusion or mental changes (especially in older adults)

Sources

FDA-approved prescribing information for Bentyl (dicyclomine hydrochloride)
American College of Gastroenterology guidelines on IBS management
Clinical pharmacology references