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What Causes Diarrhea (and How to Make It Stop)

Image of What Causes Diarrhea (and How to Make It Stop)
Image of What Causes Diarrhea (and How to Make It Stop)

Even when you’re an adult who’s dealt with it plenty of times throughout life, having diarrhea is never fun. It’s inconvenient at best, painful and debilitating at worst, and always leaves you wondering, “What did I do to make my body so unhappy?”

We’re here to help you answer that question, figure out if your diarrhea is just a passing phase or a bigger problem, and give you tips for how to control it so you can have relief (and stop constantly looking for the nearest bathroom!).

Do I have diarrhea?

You probably already know this based on your latest visit to the bathroom, but if you’re unsure whether your symptoms match up with diarrhea, here’s the gist. Diarrhea is characterized by loose, watery stools that are sometimes accompanied by:

  • Abdominal pain or cramping
  • Bloating, nausea, or vomiting
  • Fever or chills
  • Needing to go more frequently or urgently

Technically you “have diarrhea” if this happens three or more times in a day, but even if you have one watery poop you’re probably wondering what’s going on.

Your case may be acute or chronic. Acute diarrhea technically lasts less than two weeks, though most will clear up in 3-7 days. Dealing with an acute case every so often is pretty common, and most cases work themselves out on their own. If your loose stools last more than four weeks or continue recurring over time, it’s considered a chronic case and likely points to different underlying issues.

What causes diarrhea?

What’s happening in your body when you have diarrhea is pretty straightforward. All body waste starts out with a liquidy consistency when it leaves your stomach, but usually most of that liquid gets absorbed as it passes through the large and small intestines before leaving your body as solid stool. If something irritates your intestines, they can become overactive and move waste through too quickly for that absorption to happen, causing liquidy stool to come out the back end.

Now, in terms of what can cause that irritation, it gets a bit more complex.

Causes of acute diarrhea

Acute cases are typically caused by viral infections (a.k.a. a stomach flu such as norovirus or rotavirus) or bacterial contamination (a.k.a. food poisoning from things like E. coli, salmonella, listeria, or the leftovers you left a little too long in the fridge).

Less frequently it’s caused by parasites, like giardia, which can also lead to more chronic issues.

You may get “travelers diarrhea” when visiting certain countries where the water is contaminated with things your body isn’t accustomed to.

It can also be a side effect of medications, such as antibiotics, antacids, or antidepressants.

Causes of chronic diarrhea

Chronic diarrhea is more likely to point to a digestive system disorder, including:

One of the most common questions we get is, “How do I know if my diarrhea is a symptom of IBS?” The best way to tell will be to pay attention to all the symptoms you’re having and how long they’ve been happening, and then talk to your doctor.

Generally, if you’ve been experiencing bowel discomfort accompanied by abdominal pain for more than three months, IBS is a good option to explore. Another telltale sign that you could be dealing with IBS is if your bowel movements alternate between diarrhea and constipation.

What can I do to stop diarrhea right now?

If you’re able, it’s generally best to let most acute cases of diarrhea run their course. In a sense, this is your body’s way of quickly flushing out something that’s not working for it. Drink plenty of fluids to help prevent dehydration (especially beverages with sugar and salt, like Gatorade, which help with absorption), avoid any foods that may irritate the intestines more (like fried or spicy foods), and know that this too shall pass.

But if you need to stop your diarrhea, stat—like if it’s causing you a lot of discomfort or you need to be on the go without having to worry about running to the bathroom—there are plenty of over-the-counter anti-diarrheals that should do the trick.

Look for medications with active ingredients like loperamide (Imodium®), which helps slow down your intestinal function, or bismuth subsalicylate (Pepto-Bismol®), which helps slow the growth of bacteria that may be causing diarrhea. If your troubles are a result of recent travels, an antibiotic may be in order to kill off whatever's making your gut unhappy.

What can I do to help prevent chronic diarrhea?

How you prevent chronic diarrhea will depend on what you and your doctor think the underlying cause is—treating a food allergy is different than treating IBS is different than treating IBD. Your doctor will want to know about any symptoms you’re experiencing (e.g., abdominal pain), how long it’s been happening, and may recommend a stool test or colonoscopy to help determine what’s going on and get you on the right plan forward.

But if you’re looking for relief in the meantime, paying close attention to your diet is a good place to start. The best foods for diarrhea are actually those that are low in fiber, as they won’t stimulate your already irritated bowel as much.

This can include things like bananas, cooked carrots and squash, white rice or pasta, oatmeal, and smooth nut butters. You’ll also want to note if there are any foods that seem to trigger an issue and cut those out.

You also may want to experiment with probiotic supplements. While there’s still research to be done around this and some of what exists is conflicted (for example, in this study, 55 out of 100 people who took probiotics were diarrhea-free after three days, but so were 34 people out of 100 who didn’t take anything), there are few side effects and therefore a low risk in seeing if they help you.

When is diarrhea an urgent medical condition?

You’ll want to call a doctor immediately if your diarrhea:

  • Is bloody or has a black or tar-like color: This can indicate internal bleeding, which can be caused by anything from IBD to colorectal cancer to hemorrhoids, and may or may not be serious. Still, blood in the stool is always worth checking out, even if you’ve had the issue before and determined it was nothing to worry about.
  • Is accompanied by severe abdominal pain: While a little cramping is normal, severe or sudden abdominal pain—especially accompanied by other symptoms like vomiting or fainting—could point to a serious digestive condition.
  • Is accompanied by a fever of over 102 degrees Fahrenheit: A little fever with your diarrhea is nothing to sweat about—it’s common with viral infections—but if it’s extremely high or won’t let up after a few days, it’s probably a good idea to chat with your doc.
  • Is accompanied by dramatic weight loss: If you’ve dropped more than 10 pounds during your bout with diarrhea, you’ll want to check with your doctor to make sure you’re getting the nutrients you need.
  • Is causing severe dehydration: Because you’re losing so much liquid from your body without absorbing it, diarrhea can cause dehydration. If you're experiencing symptoms like headache, extreme thirst, dark urine or no urine, dizziness, fatigue, or mental confusion, seek medical attention to help get your body re-hydrated ASAP.


Nobody likes having diarrhea and somehow talking about it can be even more uncomfortable. But everybody poops and everyone has diarrhea, too, so it’s nothing to be ashamed about. Instead of feeling embarrassed by your bodily functions, let’s turn that energy into figuring out the root of the issue and alleviating your symptoms ASAP.


The information provided in this article is not a substitute for professional medical advice, diagnosis, or treatment. You should not rely upon the content provided in this article for specific medical advice. If you have any questions or concerns, please talk to your doctor.

Photo by Giorgio Trovato on Unsplash