Can the Keto Diet Cause Diarrhea?

minute read | Last update: Dec 1st2022

This article is backed by studies and reviewed by a certified dietician.

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The last thing anyone wants to talk about is their bathroom habits, but sometimes, this tough topic of conversation has to come up. For instance, you’ve noticed that since you’ve started the keto diet, you have a lot more diarrhea than you used to. Is this a coincidence or is keto the cause?

The keto diet can cause diarrhea since it’s so high in fat. The fat triggers the liver to increase its bile production, and bile happens to be a laxative as well, hence the diarrhea. By eating more fiber in your keto diet, you can lessen your diarrhea.

In this article, we’ll discuss definitively whether keto causes diarrhea as well as what you should do about it and when it’s a good time to see a doctor. Keep reading, as there’s a lot of great information ahead!

Does the Keto Diet Cause Diarrhea? Why?

The ketogenic or keto diet can cause some unwanted side effects such as the keto flu, where you experience symptoms like vomiting, nausea, moodiness, and headache. Well, now you have one more little side effect to add to that list, and that’s diarrhea.

Diarrhea is categorized as watery, loose stools. Your rate of defecating might be more than normal. Although diarrhea is usually caused by contaminated food and viruses, your diet can also affect the quality of your stools.

Why does the keto diet cause diarrhea? Well, at first, it’s due to the changes in your gut’s microbiome. The microbiome is a collection of microorganisms like eukaryotes, archaea, and bacteria in your digestive tract that keep everything in your gut healthy.

Whenever you change your diet, it shakes up your gut microbiome, so to speak. This doesn’t last long, which is why keto dieters should quickly overcome the keto flu. Some keto dieters though discover that their stomach woes continue even when the other symptoms of keto flu are long since gone.

That’s because of the composition of the keto diet. As you know, you’re reducing carbs and increasing protein and fat, and the latter is the issue. Breaking down fat is a gradual process, so it takes your body longer to metabolize it.

Fat breakdown requires bile that comes from the liver. If you eat more fat, the liver makes more bile. As we touched on in the intro, bile is more than the stuff that comes out when you puke, but it’s also a laxative.

If your liver makes a lot of bile, then as a laxative, it can send waste through your digestive track fast. Then it needs to come out, causing the urge to go the bathroom. When you defecate, it’s diarrhea.

As part of the keto diet, perhaps you upped your consumption of sugar alcohols and artificial sweeteners to help you cut your carbs. That too can upset your stomach.

According to a 2019 report in the journal Advances in Nutrition, the sugar alcohols polyol and lactitol as well as the sweetener sorbitol all act as natural laxatives. The more of them you eat on the keto diet (or in general), the more diarrhea you could have!

How to Alleviate Stomach Woes from Keto

Keto flu generally lasts about a week, and in some severe cases, up to a month. If you’re still having diarrhea after 30 days of being on the keto diet, then you can assume it might not go away on its own even though the other symptoms of the keto flu have.

You want to maintain your keto diet, but you’re tired of running to the bathroom all the time. What should you do?

Here are some tips for calming your aching stomach and righting your gut microbiome.

Eat More Fiber

Fibrous foods absorb water, which is important if you have diarrhea. After all, diarrhea occurs before the intestines can absorb all that water, which is why they’re so loose and watery. Eating fiber will firm up your stools and reduce your diarrhea.

On the keto diet, we recommend the following foods:

  • Nuts (2.5 grams of net carbs per ounce and 3.5 grams of fiber)
  • Avocado (4 grams of net carbs per avocado and 13 grams of fiber)
  • Collard greens (3 grams of net carbs per cup and 7.5 grams of fiber)
  • Artichokes (6.5 grams of net carbs per medium artichoke and 7 grams of fiber)
  • Broccoli (2 grams of net carbs per half-cup and 1 gram of fiber)

Or Take a Fiber Supplement

You’re closely monitoring your carb macros, and so you’d rather skip some of the recommended high-fiber foods. In that case, you can always start a fiber supplement routine. However, do be aware that alone, fiber supplements might not provide you with enough fiber to help with your diarrhea.

The best course of action is to combine the supplement with at least some high-fiber food.

Eat Fermented Foods

During processing, some food undergoes fermentation, which makes carbs into organic acid or alcohol through the presence of microorganisms. Fermented foods are also rich in probiotics that can repair your damaged (or disrupted) gut microbiome.

On the keto diet, kimchi is a safe bet. A cup of the stuff has 1 gram of net carbs and 2.5 grams of filling fiber. Sauerkraut contains 2 grams of net carbs and 4 grams of fiber per cup.

Maintain Your Hydration

Since diarrhea is so watery, expelling it puts you at a higher risk for dehydration. Ensure that through your beverage and dietary choices that you’re staying hydrated. Men need about 125 ounces of water per day and women 91 ounces.

When to See a Doctor about Keto Diarrhea

The above measures should help with your keto diarrhea, but in limited instances, they might not. If your diarrhea continues for two days and doesn’t improve, then it’s time to call your doctor.

You should also do that if you have a fever over 102 degrees Fahrenheit, your stools turn black and/or bloody, or you’re experiencing rectal and/or abdominal pain.

Having dehydration from diarrhea also requires medical attention. The symptoms include dark-colored urine, dizziness, weakness, reduced urination (or no urination), dry skin, dry mouth, and feeling very thirsty.


Any diet can disrupt your gut microbiome, which can lead to uncomfortable gut symptoms for a few days or weeks. The keto diet in particular is likelier to cause diarrhea because in processing all the fat you consume, your body makes more bile, a laxative.

By eating more fiber and fermented foods and taking supplements, you should notice a decrease in your rate of diarrhea. The game changer against "disaster pants" for us was to slowly increase the fats we consume. If it’s been more than a month and the diarrhea hasn’t gotten better or it gets worse, you need to see a doctor right away.

Most importantly when you’re dealing with diarrhea – stay hydrated! Dehydration can be deadly, so know the signs and always have food or beverages on hand to restore your electrolytes.

About the author

The Authentic Keto Team is here to bring you health tips that help you with losing weight fast. We focus on a clean keto diet for beginners because we believe that is the easiest and most simple way to healthy eating. Our keto weight loss tips will not only bring you into ketosis fast but will also help you to improve your mental health, sleep problems, and wellness.

- Our goal is to make keto success easy. -

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