Diarrhea that happens after you eat a meal is known as postprandial diarrhea (PD). This type of diarrhea is often unexpected, and the feeling to use the restroom can be quite urgent.
Some people with PD experience painful bowel movements (BMs). In most cases, this pain resolves after the BM.
The condition isn’t uncommon, but getting to a diagnosis can be difficult. That’s because PD is sometimes the symptom of another condition.
In other cases, PD occurs for no diagnosable reason.
The conditions or issues that can cause PD fall into two primary categories: acute, which lasts for a short duration, and chronic, which lasts long term. Keep reading to learn more.
Why it happens on occasion
Some conditions or issues may cause a brief bout of PD. Time may put a stop to the PD symptoms, or medicine may be required. These causes include:
Viral infection: Viral infections, like stomach bugs, can cause temporary PD and make your digestive tract extra sensitive. The PD may last for a few days, even after other symptoms have eased.
Lactose intolerance: People with an allergy to lactose, a type of sugar found in dairy products, may experience PD if they eat foods containing lactose. Symptoms of lactose intolerance include bloating, abdominal cramping, and diarrhea.
Food poisoning: The human body does a good job of knowing it has eaten something it shouldn’t. When it detects the bad food, your body will probably try to expel it immediately. That may cause diarrhea or vomiting within a few minutes of eating the contaminated food.
Sugar malabsorption: This condition is very similar to lactose intolerance. Some people’s bodies can’t properly absorb sugars like lactose and fructose. When these sugars enter the intestine, they can cause diarrhea and other gastrointestinal issues.
Toddler’s diarrhea: Toddlers and young children who drink a lot of fruit juice may develop PD. The high amounts of sugar in these drinks can draw water into the bowels, which can cause watery stools and diarrhea.
Parasites: Foodborne parasites can cause PD. The most common type of foodborne parasite is the tapeworm. Symptoms, including PD, will last until the parasite is removed from your body or dies.
Magnesium overdose: High levels of magnesium can cause diarrhea. However, getting too much of this mineral is difficult unless you’re taking a supplement.
Why it happens regularly
Chronic causes of PD are conditions that may need ongoing treatment in order to prevent PD symptoms. These conditions include:
Irritable bowel syndrome: IBS is a disorder that causes a variety of gastrointestinal issues. These include diarrhea, bloating, gas, and abdominal cramping. It’s not clear what causes IBS.
Celiac disease: This autoimmune condition causes damage in your intestines each time you eat gluten. Gluten is a protein found most commonly in wheat products.
Microscopic colitis: This condition causes inflammation of your large intestine. In addition to diarrhea, symptoms include gas and abdominal cramping. The inflammation isn’t always present, however. That means symptoms of PD can come and go.
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: People who have their gallbladder removed may experience frequent diarrhea in the first few weeks and months after the surgery. In most cases, the diarrhea will eventually stop, but some people will continue to have chronic diarrhea or PD after the surgery.
Dumping syndrome: This complication of weight loss surgery isn’t common, but it can be a cause of PD. With this condition, your stomach empties very quickly after eating. This triggers the reflex that manages bowel movements, so diarrhea may be more common.
If your doctor diagnoses you with IBS-D or PD, ask if it’s possible another condition is responsible for your symptoms. In some cases, an IBS-D diagnosis may prevent some doctors from considering other conditions.
Many of the conditions that cause PD require medical treatment, but these four lifestyle treatments may also ease the condition:
Avoid trigger foods: Certain foods may contribute to PD. If you aren’t sure what your trigger foods are, keep a food diary. Make note of what you eat and when you experience PD. Look for food commonly associated with PD, such as fatty foods, fiber, and dairy.
Practice food safety: Keep bad bacteria at bay by washing fruits and vegetables before eating them, cooking meat to the proper temperature, and properly refrigerating foods that need to be kept cold.
Eat smaller meals: Eat five to six small meals a day instead of three big ones. This may help your intestines more easily digest food, and that could reduce symptoms of PD.
Reduce stress: Your mind has a lot of power over your gut. When you’re stressed or worried, you may make your stomach upset more easily. Learning to manage your stress and anxiety is good not only for your mental health, but also for your digestive health.
See your doctor
Diarrhea happens from time to time. It’s not often a serious concern. However, serious complications are possible, so check with your doctor if you experience any of these additional symptoms:
Frequency: If diarrhea occurs several times a week for more than three weeks, or if you have diarrhea for three days in a row, make an appointment with your doctor.
Fever: If you have diarrhea and a fever over 102°F (38.8°C), seek medical treatment.
Pain: If the diarrhea is common but you start experiencing severe abdominal pain or rectal pain during a BM, talk with your doctor.
Dehydration: It’s important you stay properly hydrated when you have diarrhea. Drinking water or drinks with electrolytes can help you stay well despite the diarrhea. However, if you start showing signs of dehydration, seek medical attention. Signs of dehydration include:
- extreme thirst
- muscle cramps
- dark-colored urine
Discolored stool: If you start having black, gray, or bloody stools, talk with your doctor. These can be signs of a more serious gastrointestinal problem.
There isn’t one single tool or test that can help doctors identify and diagnose the source of PD. Because of this, they often recommend certain treatment options one at a time until they find one that works consistently.
When a treatment works, it helps your doctor understand what’s responsible for PD. From there, they can continue to narrow down the potential causes and come up with a full treatment plan.