Does the Keto Diet Cause Diarrhea? How it Works & Getting Relief

Key takeaways:

• The keto diet requires a strict dietary regimen that can disrupt how your gastrointestinal tract functions.
• Diarrhea associated with keto, also referred to as “keto diarrhea” is a common symptom when starting the keto diet.
• Diarrhea resolves for many people after a few days to a week once their body adjusts to the new diet.

The ketogenic diet, more commonly referred to as the keto diet, has gained immense popularity for its potential to aid in weight loss and improve certain markers of health. However, one common complaint among those who follow this way of eating is gastrointestinal side effects including diarrhea. If you are experiencing this uncomfortable symptom while consuming a keto diet, you might wonder if it is normal, how long this symptom will last, and if there is any way to prevent or improve it.

In this article, we will explore the connection between the keto diet and diarrhea, discuss potential causes, and offer tips for managing this symptom. We will also review when this symptom is no longer considered normal and when you should consult a healthcare provider.

Is it normal to have diarrhea on the keto diet?

It is not uncommon to experience digestive issues while on the keto diet. The keto diet focuses on consuming a high-fat low-fiber diet that has been linked to side effects such as diarrhea, bloating, and constipation.

Duration of diarrhea on the keto diet

Typically, diarrhea linked to the keto diet is temporary and improves as your body adjusts to this way of eating. You may experience diarrhea that can last from a few days to a couple of weeks as your body adjusts.

If diarrhea persists beyond this timeframe, you should consider other causes of your symptoms such as food intolerances or improper nutrient intake, and speak with your healthcare provider.

How the keto diet can cause diarrhea

The keto diet aims to facilitate somewhat rapid weight loss by putting the body into a state of ketosis.

In order to achieve ketosis, strict dietary guidelines must be followed that often differ greatly from what you are used to consuming. Making drastic dietary changes can be linked to gastrointestinal adverse effects such as diarrhea.

High-fat intake

The keto diet focuses on eating a low-fiber high-fat diet. It takes the body a lot of work to break down and metabolize fats compared to other nutrients. Consuming highly fatty foods is a common cause of diarrhea when the body is unable to keep up with metabolizing them fast enough.

Ketosis

The entire purpose of the keto diet is to put your body into ketosis. This is a metabolic state where the body uses fat as its primary source of fuel as opposed to carbohydrates. There are many signs and symptoms that your body is in a state of ketosis, one of which is experiencing diarrhea.

Use of artificial sweeteners

In an attempt to limit carbohydrate intake, many people on a keto diet will opt for artificial sweeteners such as sorbitol and xylitol. These artificial sweeteners are known to cause symptoms such as diarrhea.

Low-fiber intake

You may associate low dietary fiber with constipation. But did you know that greatly restricting your fiber intake can actually cause diarrhea as well?

A low-fiber diet will mean you have less undigested food moving through your bowels leading to loose stools and sometimes diarrhea.

Read our guides on what causes diarrhea and treating diarrhea for more.

How to treat diarrhea from the keto diet at home

There are some ways that you can attempt to fight off this unpleasant side effect at home. If the following suggestions do not greatly reduce or resolve your diarrhea, you should speak with your provider.

Hydration

Diarrhea can lead to a rapid loss of fluids and electrolytes and ultimately, dehydration.

Staying hydrated and drinking plenty of water and electrolyte-containing drinks is the most important first step when you experience diarrhea.

Dietary adjustments

While the keto diet focuses on high-fat, low-fiber, low-carb, and moderate protein intake, it is important to get the main nutrients of this diet from healthy sources.

Eating poor-quality fats from highly processed foods and consuming high protein intake as opposed to moderate protein intake can lead to diarrhea.

Medication

You may consider taking over-the-counter antidiarrheal medications if you are experiencing diarrhea after initiating the keto diet.

These medications are not intended to be taken long-term so if you find that you need them beyond 1-2 days, you should consult your healthcare provider to discuss the next steps.

Read our guide on treating diarrhea at home for more.

When to see a doctor about diarrhea on the keto diet

While mild diarrhea can often be managed at home, there are times when it is essential to seek medical attention. It is important to recognize when it is time to see your healthcare provider for your symptoms.

You should see a doctor if:

• Diarrhea lasts more than a few days to a week, indicating that your body is not adjusting to this new way of eating.
• You experience associated abdominal pain, nausea, or vomiting.
• You have symptoms of dehydration, such as dizziness, dry mouth, or dark urine.

You should go to the emergency room if:

• You experience signs of severe dehydration, such as weakness, or heart palpitations.
• Your diarrhea is accompanied by severe abdominal pain.
• You are unable to keep any fluids down for more than 24 hours.

Questions to ask your doctor about diarrhea on the keto diet

• Is it normal to experience diarrhea while on the keto diet?
• Are there changes I can make to my diet that help with the diarrhea while maintaining a state of ketosis?
• Are there any medications that can help with my digestive issues?
• What red flags should I look for that would indicate the need to be re-evaluated by a healthcare provider?

How a doctor may treat diarrhea from the keto diet

There are very strict dietary intake guidelines that accompany the keto diet, but sometimes it is still a struggle to get the proportions right and manage the associated side effects. Consulting your doctor and the help of other healthcare professionals such as a registered dietician can be helpful in managing keto-associated diarrhea.

Probiotics

Dietary changes can disrupt the natural balance of gut bacteria leading to digestive symptoms such as diarrhea. Your doctor may suggest taking probiotics to help maintain the normal balance within your digestive tract.

Dietician consult

Your healthcare provider may recommend you meet with a dietician to come up with a proper meal plan while on the keto diet. It is important to consume healthy fats and avoid unhealthy fats coming from highly processed foods.

Change in diet

Unfortunately for many, the keto diet is not sustainable. Aside from its highly restrictive nature, some of the unpleasant side effects may persist for weeks in certain unlucky individuals.

Experiencing symptoms such as ongoing diarrhea puts you at risk for dehydration. If you experience prolonged keto diarrhea, your healthcare provider may consider switching you to a different diet plan altogether.

Frequently asked questions: diarrhea on the keto diet

Starting a new way of eating is not easy and often comes along with many questions. Here are some of the most common questions patients have about experiencing diarrhea while on the keto diet.

Is diarrhea a symptom of ketosis?

Yes, diarrhea is a symptom that some people report experiencing when their body goes into ketosis. Digestive symptoms and changes in bowel habits such as diarrhea or constipation may be experienced when you are in ketosis.

What if you’re experiencing diarrhea for more than a few days or a week?

Many reports of diarrhea associated with the keto diet happen within the first few days to a week after starting this diet and then begin to taper off.

If you experience diarrhea for more than a week, this may be a sign that your body is not adjusting well to ketosis or that you are eating the wrong kinds of foods.

Either way, diarrhea lasting more than a week can put you at risk of dehydration due to loss of fluids and electrolytes. If you have been experiencing diarrhea for more than a week, you should speak with your healthcare provider.

The keto diet: is it worth it?

There is no shortage of scientific data showing that the keto diet has been successful in helping people achieve weight loss and managing chronic conditions such as diabetes. But there is also no shortage of information on the unpleasant side effects such as diarrhea that come along with this diet plan.

Experiencing diarrhea for a few days at the onset of the keto diet is normal, but experiencing ongoing diarrhea for weeks puts you at risk for dehydration and is a sign that this may not be the diet for you. Keep in mind that there are many other diet options available to you that you can discuss with your healthcare provider if you experience severe or ongoing side effects like diarrhea while on the keto diet.

General Medicine follows a strict editorial process, including using real experts to write our articles, vetted primary sources, fact-checking, a secondary medical review, and updates as necessary. This article was medically reviewed and fact checked by Dr. Lane Thaut, DO.

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