Alcohol can affect the way your body digests food. Whether you develop constipation or diarrhea may depend on how much you drink. People with certain health conditions may also be more likely to experience diarrhea after drinking.

Small amounts of alcohol may cause the digestive system to work more quickly than usual, which can result in diarrhea.

On the other end of the spectrum, drinking large amounts of alcohol can delay digestion and cause constipation.

But any level of alcohol consumption can cause internal irritation and inflammation.

If you’re already dealing with an upset stomach or a touch of diarrhea, drinking alcohol may make your symptoms worse.

Fiber-rich or greasy foods — common home remedies for hangover symptoms — can also can also speed up digestion.

Alcohol is absorbed into the bloodstream. This process starts as soon as alcohol enters the body. Some of this absorption occurs in the stomach.

If there’s food in your stomach, it’ll act as a “buffer,” slowing the rate of alcohol absorption. Some of the food’s nutrients will be absorbed alongside the alcohol through the cells in your stomach wall.

If your stomach is empty, there’s nothing else for your body to absorb. The alcohol will continue to your small intestine where it similarly passes through the cells of the intestinal wall, but at a much faster rate.

In either scenario, most of the alcohol is absorbed in the small intestine. Whatever is left travels through the large intestine, where liquid is typically pulled out of stool so that it’s somewhat firm when exiting the body.

Your colon — the longest part of your large intestine — muscles move in a coordinated squeeze to push stool out.

Alcohol can cause these muscles to contract more frequently, moving stool out of the body before liquid can be absorbed by the large intestine. The end result is diarrhea.

People who have bowel diseases may be more reactive to alcohol and may be more likely to experience alcohol-induced diarrhea as a result.

This includes:

Some research suggests that a lack of regular sleep can make the digestive system more sensitive to the effects of alcohol.

People with irregular sleep schedules — including those who work night shifts or frequently pull all-nighters — may be more likely to experience diarrhea after drinking alcohol.

If you refrain from drinking, most alcohol-induced cases of diarrhea will clear up in a few days. But there are some things you can do to further ease your symptoms:

  • Limit or avoid caffeine. Coffee, soda, and other caffeinated or carbonated drinks can worsen diarrhea.
  • Stay hydrated. Water, broth, and other liquids can help restore your electrolytes and prevent dehydration.
  • Stick to bland foods. Bananas, crackers, and toast, for example, are easily digestible and unlikely to cause further irritation.
  • Use anti-diarrheal medication as directed. Loperamide (Imodium) can help slow or stop diarrhea. Bismuth subsalicylate (Pepto-Bismol) can also help with upset stomach and other related symptoms.

If diarrhea lasts for more than 2-3 days or worsens over time, consult with a healthcare professional.

They can help determine if your symptoms were brought on by more than just alcohol. In some cases, persistent diarrhea can be a sign of an underlying condition.

You should also seek medical treatment if you:

  • have a fever higher than 102°F (39°C)
  • have intense abdominal or rectal pain
  • have stool that’s black (that isn’t caused by an antidiarrheal medication)
  • have stool that’s bloody
  • have signs of dehydration, such as dizziness, dark urine, or inability to pee for some time

Alcohol-related diarrhea typically resolves after a few days of at-home care. Taking steps to prevent dehydration can help prevent additional complications.

If you have questions about the way your body reacts to alcohol or concerns about use, you might consider reaching out to a healthcare professional.