Can Alcohol Cause Diarrhea?

Last night was fun. Maybe a little too fun? An evening of drinking can leave you feeling lousy and, sometimes, with a case of the runs (aka diarrhea).

“The stereotypical symptoms of a hangover are headache, nausea and fatigue. Many people aren’t aware that diarrhea is also a frequent symptom,” says gastroenterology nurse practitioner Bryn DeSantis, CNP.

DeSantis explains what alcohol does to your gut, how to feel better and ways to prevent alcohol-related diarrhea.

Why does alcohol cause diarrhea?

Alcohol may make you feel great in the moment, but in large volumes, it can have some negative effects. It even has a direct link to cancer.

“In your digestive tract, alcohol disrupts normal function and your ability to digest food properly,” DeSantis says. This disruption causes:

• Excess water in your gut. Typically, water gets absorbed out of your intestines, helping solidify stool. But alcohol draws water into your intestinal tract, acting like a laxative. The excess water makes stools loose and can lead to diarrhea.
• Faster gut transit. Alcohol also speeds up the contractions in your digestive system. The result: cramping and an urge to poop.
• Inflammation. Alcohol irritates your intestines. The resulting inflammation contributes to diarrhea by speeding up digestion.
• Variations in gut bacteria. Your intestines are home to a thriving community of bacteria (microbiome). Excess alcohol use can upset the balance of “good” and “bad” bacteria.

Who’s most at risk for diarrhea from alcohol?

Those most at risk are people with certain digestive diseases, including:

• Carbohydrate intolerance: Some people have trouble digesting certain carbohydrates, like fructose, that are common in wine, beer and mixers.
• Celiac disease, non-celiac gluten sensitivity and wheat allergy: People with these conditions react to gluten. Most wines and spirits are gluten-free. But be careful of beer, which is often made from gluten-containing wheat.
• Inflammatory bowel disease (IBD): IBD includes ulcerative colitis and Crohn’s disease. Because alcohol is an irritant, it can worsen IBD symptoms and flares.
• Irritable bowel syndrome (IBS): IBS causes abdominal pain, bloating and changes in bowel movements. IBS triggers vary but may include certain alcoholic beverages and mixers.

It’s also possible to have an intolerance to alcohol itself, says DeSantis. Alcohol intolerance is an inherited condition that affects your ability to break down alcohol. Symptoms occur with even small amounts of alcohol and include:

• Flushing
• Diarrhea
• Fatigue
• Headache
• Nausea and vomiting

What types of alcohol have a greater chance of causing diarrhea?

High-carb options, such as beer and sugary alcoholic beverages, may be more likely to cause diarrhea. That’s because the bacteria in your large intestine break down the excess carbs for energy, which can lead to gas and diarrhea.

“Mixing alcohol with caffeinated beverages, such as energy drinks, can also make diarrhea worse,” DeSantis notes. “The caffeine in these beverages stimulates intestinal motility, which contributes to diarrhea. It adds to the dehydration caused by alcohol. Caffeine can also mask intoxication, making you drink more.”

But unless you have a digestive condition or carbohydrate intolerance, the alcohol type probably matters less than how much you drink.

The standard alcohol drink size is:

• Beer: 12 ounces of 5% alcohol, about one can
• Distilled spirits: 1.5 ounces of 40% alcohol (80 proof), about one shot
• Wine: 5 ounces of 12% alcohol, about one glass

When you pour a drink at home or order one out, the amount of alcohol can be deceiving, DeSantis cautions. For example, most wine glasses hold much more than the recommended serving size of 5 ounces. And many beers exceed 5% alcohol content.

How to stop diarrhea after drinking alcohol

As with other hangover symptoms, the main remedy for diarrhea after drinking is patience. How long does alcohol diarrhea last? Your symptoms should clear up within 24 hours, depending on how much alcohol you consumed.

While you wait, drink plenty of water to counter the dehydrating effects of alcohol. Bland foods can also help prevent further intestinal distress.

“If diarrhea is severe, an over-the-counter antidiarrheal medication may also help,” DeSantis shares. “These medications slow the movement of waste through the colon, giving more time for stool to form.”

Preventing diarrhea from alcohol

Most diarrhea that results from drinking alcohol is short-lived. But if you want to prevent alcohol-related diarrhea from happening altogether, the most effective way is to drink less or stop drinking. If that advice doesn’t fit your lifestyle, other tips can help reduce the effects of alcohol:

• Avoid caffeine. Caffeine can worsen diarrhea, so avoid it when you’re consuming alcohol.
• Curb tobacco use. Smoking and drinking are both intestinal stimulants and can be a diarrhea double whammy.
• Eat food. It’s easy to forget to eat when you’re drinking. But food can help slow the breakdown of alcohol and offset some of its negative effects.
• Stay hydrated. For every alcoholic drink, consume a glass of water. The extra fluid helps dilute the alcohol and may help you drink less.
• Take it slow. Limit yourself to one standard drink per hour. This allows your body enough time to process the alcohol.

When to call a healthcare provider for diarrhea after alcohol

In general, it’s rare to require medical care for alcohol-related diarrhea, DeSantis says. If you experience symptoms every time you consume alcohol or even when consuming small amounts, talk to your provider.

Also, let your provider know right away if you experience more severe gastrointestinal symptoms, such as:

• Diarrhea that lasts for more than a few days
• Rectal bleeding
• Significant abdominal pain
• Unintentional weight loss

An evaluation can help determine what’s causing your symptoms. And if you’re sober curious, a visit with a provider is a great opportunity to discuss steps you can take to quit alcohol for good.