One of the most common (and easily fixable) medication mismatches I see in practice involves bowel regimens that outlive their original purpose. This is a great example of how deprescribing can reduce pill burden and prevent unnecessary adverse effects.

Bowel Regimens – Case Study

Let’s walk through a case.

A 79-year-old female with a history of osteoarthritis, hypertension, and mild cognitive impairment is admitted to a transitional care unit after a hip fracture. During her hospital stay, she required scheduled oxycodone for pain control. As expected, she developed opioid-induced constipation and was started on a bowel regimen including senna 2 tabs twice daily and polyethylene glycol 17 grams daily. She was also taking oxybutynin for overactive bladder, which added additional anticholinergic burden and likely contributed to constipation.

Over the next few weeks, her pain improved significantly. The care team appropriately discontinued her scheduled oxycodone and transitioned her to as-needed acetaminophen. Around the same time, her oxybutynin was also stopped due to concerns about cognitive side effects (excellent board exam nugget to remember) and anticholinergic burden.

So far, this is excellent deprescribing.

However, about a few days later, the patient begins experiencing multiple loose stools per day. Nursing documents 4–5 bowel movements daily, and the patient reports urgency and mild abdominal cramping. There are no signs of infection, no recent antibiotic use, and no red flags like blood in the stool.

At this point, it’s tempting to start thinking about adding a new medication—maybe loperamide.

But this is where we should pause and look upstream.

What changed?

We removed two constipating medications: a scheduled opioid and an anticholinergic. However, we left behind an aggressive bowel regimen that was originally designed to counteract those very effects.

This is a classic “prescribing cascade in reverse.”

The laxatives are no longer matching the patient’s needs. What was once necessary is now excessive.

The fix here is simple and high yield: deprescribe or reduce the laxatives.

In this case, stopping the senna and reducing polyethylene glycol to as-needed resulted in resolution of the diarrhea within a few days. No new medications were required.

This is a great reminder of a few key principles:

Always reassess bowel regimens when stopping constipating medications like opioids or anticholinergics.
Diarrhea in older adults is often medication-related and not always a signal to add another drug.

Deprescribing is not just about stopping high-risk medications—it’s also about cleaning up the “supporting” medications that are no longer needed. Reducing unnecessary laxatives can meaningfully decrease pill burden and improve quality of life.

This type of scenario is low-hanging fruit for pharmacists and clinicians. It’s a simple intervention, but one that can prevent discomfort, reduce medication load, and reinforce thoughtful prescribing.

Next time you see diarrhea in a patient who recently had medications stopped, take a close look at what might have been left behind.