How Metformin Works
Understanding how metformin functions can help explain why diarrhea is a potential reaction.
Improves Insulin Sensitivity
Metformin makes your body's cells more sensitive to insulin produced by your pancreas. This allows better insulin absorption to regulate blood sugar.
Lowers Glucose Production
Your liver produces glucose when you have depleted immediate energy stores. Metformin signals your liver to slow down glucose production to prevent high blood sugar.
Increases Glucose Absorption
Metformin enables your intestines to better absorb glucose from the food you eat so it can be used for energy production.
Why Metformin Causes Diarrhea
There are a few reasons why diarrhea is a common side effect of taking metformin.
Excess Glucose in Digestive Tract
Since metformin enables intestines to absorb glucose better, more of it remains in your digestive tract, which draws fluid into the bowels and stimulates faster transit causing diarrhea.
Altered Gut Bacteria
Metformin changes the types and amount of bacteria in your intestines, particularly by suppressing unhealthy bacteria. This can also lead to GI issues like diarrhea as gut flora regulates digestion.
Intolerance Reaction
Some individuals do not properly digest or break down metformin effectively. The medication moves rapidly through the system, resulting in loose, watery stools.
Tips to Alleviate Metformin Diarrhea
Diarrhea caused by metformin is usually mild. Making certain lifestyle modifications and using over-the-counter treatments can help manage this unpleasant reaction.
Adjust Timing of Doses
Take your metformin dose during or directly after meals, split up doses evenly with meals, or switch to extended-release tablets to reduce diarrhea episodes.
Lower Metformin Dose
Speak to your doctor about potentially decreasing your metformin dose, which may relieve diarrhea. Work back up to target therapeutic dose slowly.
Avoid Trigger Foods
Eliminate hard to digest foods like dairy, cruciferous vegetables, caffeine, alcohol and high fiber cereals if you notice they provoke diarrhea episodes after taking metformin.
Up Fiber Intake
Gradually boost daily soluble fiber consumption from foods like oats, nuts, beans and fruits. Fiber regulates digestion and promotes gut health to alleviate diarrhea.
Stay Hydrated
Drink extra fluids like water and electrolyte beverages when taking metformin to counteract fluid losses from frequent stools. Prevent dehydration.
Take Over-the-Counter Anti-Diarrheals
Consider using Immodium or diarrhea relief capsules containing bismuth subsalicylate. Use sparingly per package instructions until metformin diarrhea subsides.
When to See Your Doctor About Metformin Diarrhea
Schedule an appointment with your healthcare provider if any of the following apply:
- Diarrhea persists for more than 2 weeks
- Stools contain blood or mucus
- You experience abdominal cramping or pain
- You have a fever over 101F
- Dehydration symptoms arise like dizziness or dark urine
Relay all your symptoms to your doctor. They may adjust dosage, switch you to extended-release metformin tablets, or prescribe supplemental medications to alleviate diarrhea.
Testing for Other Conditions
If diarrhea and digestive upset continues, your doctor may order tests like a complete blood count, stool sample analysis or abdominal CT scan. This allows them to check for other possible gastrointestinal issues provoking diarrhea.
Making Dietary Changes to Help With Diarrhea
Adjusting what foods you eat while taking metformin can minimize diarrhea episodes.
Choose High Fiber Grains & Produce
Fill your diet with fiber-rich oatmeal, quinoa, fruits and vegetables (without skins). Fiber normalizes bowel movements. Cook produce to make it easier to digest.
Eat Fermented Foods
Add yogurt, kefir, sauerkraut, kimchi and other probiotic-rich items provide healthy bacteria to restore gut balance and firm up stools.
Stay Well Hydrated
Frequently sip water, fruit-herb iced tea, bone broth, and electrolyte drinks to counteract fluid loss from diarrhea episodes.
Limit Sugar Alcohol Intake
Avoid too many sweeteners like malitol and xylitol found in sugar-free foods. Consuming excessive amounts can have a laxative effect.
Reduce Fat Consumption
Limit high fat meats, fried foods, heavy cream, butter and oil, which can worsen GI distress. Favor baked, grilled and broiled options cooked in moderation.
Complementary Therapies to Alleviate Diarrhea
Certain alternative medicines and stress reduction techniques may also help relieve metformin-provoked diarrhea.
Acupuncture
Acupuncture performed by a licensed practitioner can improve gastrointestinal functioning and reduce loose stools.
Peppermint Oil Capsules
Enteric coated peppermint oil capsules can relax digestive muscles and ease diarrhea-predominant IBS linked to metformin use.
Probiotic Supplements
High quality probiotic supplements support healthy gut flora compromised by metformin use to firm up stools.
Relaxation Techniques
Stress exacerbates gastrointestinal issues. Set aside time each day to practice breathing exercises, meditation, yoga, or Tai Chi to calm your nervous system.
Medication Alternatives if Diarrhea Persists
Consult your doctor about switching diabetes medications if troublesome diarrhea continues for more than 3-4 weeks despite implementing lifestyle remedies and dietary modifications.
Acarbose (Precose)
Acarbose slows carbohydrate digestion like metformin, but with fewer gastrointestinal side effects for some patients.
DPP-4 Inhibitors
DPP-4 inhibitors like saxagliptin (Onglyza) and sitagliptin (Januvia) regulate insulin levels but with less risk of diarrhea.
GLP-1 Receptor Agonists
Injectable GLP-1 drugs like liraglutide (Victoza) stimulate natural insulin production while suppressing appetite, leading to weight loss and improving glucose control.
SGLT2 Inhibitors
Medications like empagliflozin (Jardiance) and canagliflozin (Invokana) lower blood sugar by blocking renal glucose reabsorption in the kidneys.
The Takeaway
Metformin benefits most patients with type 2 diabetes thanks to its glucose-lowering effects. But gastrointestinal discomfort in the form of diarrhea affects up to 30% of metformin takers.
Adjusting dosage timing, avoiding trigger foods, upping soluble fiber intake, staying hydrated and using over-the-counter anti-diarrheals can alleviate this troublesome reaction.
See your doctor if diarrhea persists after 2 weeks or leads to complications. They can adjust your metformin prescription, run tests to check for other conditions, or prescribe alternatives like DPP-4 inhibitors that may better agree with you.
FAQs
Why does metformin cause diarrhea?
Metformin causes excess glucose in your digestive tract, alters gut bacteria, and some people don't properly digest it. These factors draw fluid into the bowels, stimulating diarrhea.
How long does metformin diarrhea last?
Metformin diarrhea usually resolves within 1-2 weeks as your body adjusts to the medication. See your doctor if it persists beyond 2 weeks despite home remedies.
What can I take for metformin diarrhea?
Over-the-counter anti-diarrheals like Immodium, adjusting timing of metformin doses, avoiding trigger foods, staying hydrated, and taking probiotic supplements can help treat metformin diarrhea.
When should I call my doctor about diarrhea?
Contact your doctor if diarrhea lasts longer than 2 weeks, you have abdominal pain, bloody stools, fever over 101°F, or dehydration symptoms. They may adjust your metformin prescription.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.
Add Comment