Several conditions, such as lactose intolerance, food poisoning, IBS, and celiac disease, can cause diarrhea after eating. Treatment will depend on the underlying cause.

Diarrhea that happens after eating is known as postprandial diarrhea (PD). This type of diarrhea is often unexpected, and the feeling to use the restroom can be quite urgent.

Acute PD is when diarrhea lasts 1-2 days, while chronic PD is when symptoms of diarrhea last longer than 4 weeks.

PD isn’t uncommon, but getting a diagnosis may be difficult because it’s sometimes a symptom of another condition.

Some conditions or issues may cause a brief bout of PD.

Viral infections

Viral infections like rotavirus and norovirus may cause temporary diarrhea and make your digestive tract extra sensitive. Diarrhea may last for a few days, even after other symptoms have eased.

Lactose intolerance

People who are lactose intolerant can’t fully digest lactose, a type of sugar found in dairy products. You may experience the following symptoms after eating foods with lactose:

Food poisoning

Nearly 48 million people in the United States get diarrhea from a foodborne illness every year, according to the Centers for Disease Control and Prevention (CDC).

Food poisoning is caused by eating food contaminated with bacteria, such as:

Sugar malabsorption

Sugar malabsorption is similar to lactose intolerance. Your body may not have the enzyme to break down fructose-1-phosphate properly.

When these sugars enter the intestine, you may experience diarrhea and the following symptoms:

Toddler’s diarrhea

Toddler’s diarrhea refers to chronic diarrhea in children ages 1-5.

It isn’t clear what causes toddler’s diarrhea. However, some potential causes include:

  • drinking too much fruit juice
  • consuming too much fiber
  • fast gut transit time


Foodborne parasites can cause PD. The most common types of foodborne parasites are:

Magnesium overdose

High levels of magnesium can cause diarrhea. However, getting too much of this mineral is difficult unless you take a supplement.

Causes of chronic PD are conditions that may need ongoing treatment.

Irritable bowel syndrome (IBS)

IBS refers to a variety of gastrointestinal symptoms that typically happen together. Your symptoms may vary in severity and duration.

These may include:

It’s not clear what causes IBS. However, eating certain foods and stress may trigger or worsen your symptoms.

Celiac disease

This autoimmune condition causes damage in your intestines each time you eat gluten, which is a protein found in wheat products.

Approximately 2 million people have celiac disease in the United States, according to CDC.

Microscopic colitis

There are two types of microscopic colitis, which causes inflammation of your large intestine.

Collagenous colitis is when a thick collagen layer forms on the tissue of your colon, while lymphocytic colitis is when lymphocytes form on the colon tissue.

Symptoms of microscopic colitis may include:

  • diarrhea
  • abdominal pain
  • an urgent need to have a bowel movement
  • fatigue
  • weight loss
  • problems controlling your bowel

Bile acid malabsorption

Your gallbladder produces bile to help break down and digest fats in your food. If these acids aren’t properly reabsorbed, they may irritate your large intestines. This can lead to watery stools and diarrhea.

Gallbladder removal

You may experience frequent diarrhea in the first few weeks and months after getting your gallbladder removed.

In most cases, diarrhea will eventually stop. However, some people will continue to have chronic diarrhea or PD after the surgery.

Dumping syndrome

Dumping syndrome happens when food in your stomach moves too quickly into your small intestine after eating. This triggers the reflex that manages bowel movements so that diarrhea may be more common.

Early dumping syndrome is when you experience diarrhea within 30 minutes of eating. Late dumping syndrome is when symptoms occur 1-3 hours after eating.

This condition is a complication of stomach, esophagus, or weight loss surgery.

There are several treatment options for acute PD, which may include:

Conditions that cause chronic PD may require medical treatment.

Before starting any treatment for PD, it’s important to speak with a doctor. They’ll be able to assess your symptoms, provide a diagnosis, and develop a treatment plan for you.

Diarrhea happens from time to time, and it’s not often a serious concern.

However, speak with a doctor if you’re experiencing the following symptoms, as these may be a sign of an underlying condition that needs medical attention:

What causes you to have diarrhea every day if you aren’t sick?

Some chronic conditions may sometimes cause you to have frequent bouts of diarrhea without any additional symptoms. These conditions may include:

That said, most of these conditions will be accompanied by other symptoms.

Why do you get diarrhea right after eating?

Diarrhea after eating can result from food intolerances, infections, or conditions like IBS.

It happens when the digestive system reacts to food, speeding up bowel movements. Certain foods, especially high fat or spicy ones, can also trigger this response.

Identifying the specific triggers through a food diary and seeking medical advice can help manage this issue.

How long does it take for diarrhea to happen after you eat?

Depending on what’s causing your diarrhea, you may experience PD within 30 minutes of eating.

What are the four types of diarrhea?

Diarrhea may be classified into four categories:

  • Acute diarrhea is when diarrhea lasts less than 2 weeks.
  • Chronic diarrhea is when diarrhea lasts longer than 4 weeks.
  • Infectious diarrhea is typically caused by a viral infection and commonly results in acute diarrhea.
  • Non-infectious diarrhea may be a side effect of taking medications or caused by a condition, such as malabsorption and IBS.

Postprandial diarrhea (PD) may happen as soon as 30 minutes after eating or may have a more delayed onset.

It’s important to speak with a doctor if you’re experiencing diarrhea for more than 2 days or additional symptoms, such as fever, vomiting, or fatigue. This may be a sign of an underlying condition needing medical attention.

Treatment for PD will depend on its cause. However, a treatment plan may include a combination of home remedies, over-the-counter medications, or prescribed medications.