Can Bentyl (dicyclomine) and Questran (cholestyramine) be started together for Irritable Bowel Syndrome (IBS)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: June 22, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Research

Starting both Bentyl (dicyclomine) and Questran (cholestyramine) together for IBS treatment is generally not recommended as a first-line approach. It's preferable to start with one medication, typically Bentyl, and assess its effectiveness before adding another. Bentyl is an antispasmodic that works by relaxing the smooth muscles in the digestive tract to reduce cramping and pain, usually dosed at 10-20 mg three to four times daily 1. Questran primarily binds bile acids to treat diarrhea-predominant IBS, typically dosed as 4 g once or twice daily mixed with fluid. These medications work through different mechanisms and may cause different side effects that could be difficult to attribute to a specific drug if started simultaneously. Bentyl may cause dry mouth, blurred vision, and constipation, while Questran can cause constipation, bloating, and may interfere with the absorption of other medications. If both medications are deemed necessary, they should be taken at least 2-4 hours apart, as Questran can bind to and reduce the effectiveness of many oral medications, including Bentyl 2. A stepped approach allows for better assessment of individual medication benefits and side effects.

Some key points to consider when treating IBS include:

  • The importance of establishing a good physician-patient relationship and educating patients about their condition 3
  • The use of dietary modifications, pharmacotherapy, and behavioral strategies tailored to the individual 3
  • The potential benefits of alternative therapies, such as relaxation techniques and hypnosis, for patients who fail to respond to conventional measures 3
  • The need to carefully assess individual medication benefits and side effects, particularly when using multiple medications 1

In terms of specific medication management, the evidence suggests that:

  • Loperamide, psyllium, bran, lubiprostone, linaclotide, and rifaximin have demonstrated improvements in specific IBS symptoms 1
  • Peppermint oil and amitriptyline may also be effective in reducing IBS symptoms 1
  • New medications, such as the dual μ-opioid receptor agonist and δ-opioid antagonist, JNJ-27018966, are being investigated for the treatment of IBS 1

Overall, a stepped approach to medication management, starting with a single medication and assessing its effectiveness before adding another, is recommended for the treatment of IBS. This approach allows for better assessment of individual medication benefits and side effects, and can help to improve treatment outcomes for patients with IBS.

References

Research

Therapeutic strategy for the irritable bowel syndrome.

The Italian journal of gastroenterology, 1991

Research

Irritable Bowel Syndrome.

Current treatment options in gastroenterology, 1999

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.