MiraLAX is a popular over-the-counter laxative used to treat constipation. It contains polyethylene glycol 3350, which works by drawing water into the intestines to soften and ease passage of stool. While MiraLAX is generally considered safe when used as directed, some people report side effects like diarrhea, bloating, gas, and green poop.
What causes green poop after taking MiraLAX?
There are a few potential reasons why your poop may turn green after taking MiraLAX:
- Accelerated transit time – MiraLAX draws fluid into the intestines, which speeds up the transit time of stool. This shorter transit time reduces the amount of bile that has time to break down and give stool its normal brown color.
- Increased bile – The polyethylene glycol in MiraLAX can stimulate bile release. More green bile pigment mixing with stool can lead to greenish poop.
- Changes to gut bacteria – Some studies suggest MiraLAX may alter gut bacteria balance. Shifts in bacteria species that process bile acids could affect stool color.
- Dietary factors – Eating a lot of green foods like leafy greens, green juices, spirulina, chlorophyll supplements, or blue/purple foods like blueberries could tint poop green.
How long does green poop after MiraLAX last?
In most cases, green stool after taking MiraLAX is temporary and subsides once you stop using it. The green color is harmless and should resolve within a couple days as your digestive system gets back to normal.
However, if you experience persistent green stool along with other symptoms like diarrhea, abdominal pain, nausea, or bloating, talk to your doctor to rule out potential underlying conditions.
Tips to prevent green stool with MiraLAX
While green poop from MiraLAX is usually nothing to worry about, here are some tips that may help prevent it:
- Stay hydrated – Drink plenty of fluids while taking MiraLAX to help soften stool and support healthy transit time.
- Slow dosage – Gradually increase MiraLAX dosage to the effective amount rather than starting with the maximum dose.
- Avoid green foods – Limit high-chlorophyll green foods, juices, or supplements that could tint stool.
- Take probiotics – Probiotic supplements may help support healthy gut flora balance.
- Increase fiber – Getting more fiber from whole grains, fruits, veggies can help normalize bowel movements.
When to see a doctor
In most instances, green stool after taking MiraLAX is harmless and will resolve on its own. However, see your doctor if you have:
- Prolonged green stool beyond a couple days after stopping MiraLAX
- Intense or painful abdominal cramping
- Diarrhea lasting more than 2 days
- Bloody or black sticky stool
- Fever or vomiting
- Signs of dehydration like excessive thirst, dry mouth, dizziness
These symptoms could indicate potential medical issues like gastrointestinal infection, inflammatory bowel disease, bile duct obstruction, or side effects from medication.
When is green poop normal?
Green stool is typically normal and harmless in the following situations:
- Babies breastfed – Early breastmilk contains nutrients that can cause greenish stool.
- Food coloring – Consuming large amounts of blue, green, or purple artificial coloring can tint poop.
- Leafy greens – Eating a lot of leafy greens like spinach provides natural green pigments.
- Iron supplements – Iron supplements can turn stool dark green or black.
- Quick transit – Stool passing rapidly through intestines may not brown from bile pigments.
However, if you suddenly start having green stool with no known cause, or other symptoms accompany it, check with your doctor to rule out potential issues.
When to worry about green poop
While usually harmless, contact your doctor if green stool is accompanied by:
- Severe diarrhea lasting over 48 hours
- Intense abdominal pain or cramping
- Bloating or swelling
- Nausea or vomiting
- Fever over 101 F (38 C)
- Bloody or black tarry stool
- Significant unintentional weight loss
These symptoms could potentially indicate an underlying condition requiring medical treatment, such as:
- Gastroenteritis – inflammation of the GI tract from a viral or bacterial infection
- IBD – inflammatory bowel diseases like Crohn’s or ulcerative colitis
- Gallstones – bile duct obstruction causing greenish stool and pain
- Pancreatitis – inflammation of the pancreas disrupting digestion
- Celiac disease – reaction to gluten that damages the small intestine
- Cancer – green stool can rarely be a sign of cancerous tumors
Seeing your doctor can help diagnose any underlying issue and provide appropriate treatment.
Key takeaways
- Green stool is a common temporary side effect of the laxative MiraLAX.
- It’s typically harmless and resolves within a couple days of stopping the medication.
- Staying hydrated, adjusting dosage, and limiting green foods may help prevent it.
- Contact your doctor if green stool persists or is accompanied by severe symptoms.
- While usually normal, green poop can occasionally indicate a medical issue needing evaluation.
| Green Poop Situation | Key Characteristics |
|---|---|
| From MiraLAX use | Starts after beginning medication, lasts 1-2 days after stopping, no other symptoms |
| Food-related | Associated with green, blue, or purple food coloring agents |
| Health condition | Persists beyond a few days, additional symptoms present like diarrhea or pain |
When to see your doctor
Schedule an appointment with your healthcare provider if you experience:
- Persistent green stool beyond a couple days
- Severe abdominal pain, cramping, or bloating
- Prolonged diarrhea or vomiting
- Unexplained weight loss
- Bloody or black stool
- Fever over 101 F (38 C)
These symptoms could indicate an underlying health issue needing medical evaluation. Prompt diagnosis can get you the proper treatment to resolve green stool from an infection, IBD, bile obstruction, or other gastrointestinal problem.
Bottom line
Green poop is an expected temporary side effect after taking MiraLAX as a laxative. It’s typically harmless and will resolve as your body adjusts and you discontinue the medication. However, if green stool persists or you have worrisome symptoms, check with your doctor to address any potential medical cause. With a proper diagnosis, you can get treatment to help return your bowel movements back to normal.
