How does alcohol use affect bowel movements?

To answer the question of does alcohol affects bowel movements, yes, it does. It is quite common to experience diarrhea after alcohol consumption. 

If you drink alcohol, you may be wondering if it affects your gastrointestinal (GI) tract and if it can cause problems with bowel movements. Alcohol use can affect all systems within the body, including the GI tract.

Article at a Glance:

Several key takeaways about alcohol and bowel movements include:

Alcohol can significantly affect bowel movements

Alcohol use affects the large intestine, causes impaired nutrient absorption, worsens symptoms of IBS, causes dehydration and may lead to internal bleeding

Chronic alcohol use may lead to severe effects like internal bleeding in the GI tract

Stay hydrated when drinking alcohol to avoid bowel-related side effects

Speak with a medical professional if you experience any concerning bowel-related symptoms after alcohol use

How Alcohol Affects Bowel Movements

To understand how alcohol affects the GI tract, it’s important to know how the GI tract functions in the presence of alcohol. 

When alcohol is ingested, most of it is absorbed into the bloodstream from the stomach and the upper part of the small intestine. If food is present in the stomach and small intestine, the absorption of alcohol will be slower. Alcohol is also an irritant to the stomach and can cause stomach inflammation called gastritis.

Related Topic: Alcohol gastritis treatment

Faster Contractions of the Large Intestine

Some of the alcohol that wasn’t absorbed in the upper GI tract will make its way to the large intestine, where it can cause the large intestine to contract, or squeeze, faster than it normally would. 

Since the large intestine is the area in the GI tract where water is usually absorbed back into the body with slow squeezing movements, the quicker contractions don’t allow for as much water to be absorbed as usual. More water remains in the large intestine because of this, which leads to the formation of watery stool and diarrhea.

Impaired Nutrient Absorption

Since alcohol causes the intestines to move faster than normal, sometimes nutrients from food aren’t absorbed well. Over a long time, this effect can result in nutrient deficiencies and malnutrition, and often requires supplementation and medical attention.

Irritable Bowel Syndrome (IBS)

Alcohol can also trigger irritable bowel syndrome (IBS). Unfortunately, IBS is a common condition that affects the GI tract, the cause of which is unknown. A person who has IBS may experience worsened symptoms when consuming alcohol.

People with other GI diseases like Crohn’s disease and celiac disease may also experience additional, or worsened, symptoms when drinking alcohol.

Diarrhea and Dehydration

Alcohol is a diuretic, which means it increases urine volume and causes the need to urinate frequently. Alcohol’s diuretic effects can lead to dehydration. It’s important to note that alcohol-related diarrhea can also cause dehydration, which can be severe. If you are experiencing alcohol-induced diarrhea, stay hydrated by drinking plenty of water.

If you notice symptoms related to alcohol consumption that last more than a day or two, it is a good idea to seek the advice of a medical professional. Symptoms that can indicate serious problems related to dehydration are dizziness, weakness, lightheadedness and sleepiness. Sometimes taking an anti-diarrheal medication like Pepto Bismol can decrease the diarrhea symptoms.

Internal Bleeding

Long-term alcohol abuse can cause bleeding in the stomach and intestines as well. If there is bleeding in the upper GI tract, the blood will turn dark (almost black) when it makes its way to the large intestine where stool is formed. If you notice dark, or black, stool it could signify bleeding in the stomach which requires medical attention.

Effects of Alcohol on the GI Tract

Alcohol can cause negative effects on the GI tract in several different ways. Especially with long-term and heavy alcohol use, these effects can be serious and require medical attention.

These effects include: 

  • Dehydration
  • Diarrhea
  • Bleeding in the stomach or intestines
  • Reduced nutrient absorption
  • Stomach inflammation (gastritis)
  • Triggering of irritable bowel syndrome (IBS) or Crohn’s disease flares

Ways to Lessen the Effects of Alcohol on the GI Tract

One way to avoid the negative symptoms of alcohol consumption is not to drink alcohol. Avoiding alcohol is not always a viable solution for some people. 

If you are going to drink alcohol, there are ways to lessen alcohol’s effects on the GI tract, including:

  • Drink only in moderation (one drink a day for women, two drinks a day for men)
  • Don’t ingest drinks that are high in sugar or artificial sweeteners
  • Drink plenty of water while drinking alcohol
  • Avoid drinks with caffeine, since this can dehydrate you even more
  • Avoid drinking on an empty stomach

If you or a loved one uses alcohol and suspect that it is causing problems, consider seeking professional assistance. The Recovery Village can help with personalized treatment for alcohol addiction. Contact us today to discover more about your treatment options.

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Editor – Camille Renzoni
Cami Renzoni is a creative writer and editor for The Recovery Village. As an advocate for behavioral health, Cami is certified in mental health first aid and encourages people who face substance use disorders to ask for the help they deserve. Read more
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Medically Reviewed By – Christina Caplinger, RPh
Christina Caplinger is a licensed pharmacist in both Colorado and Idaho and is also a board-certified pharmacotherapy specialist. Read more

Bujanda, Luis. “The Effects of Alcohol Consumption Up[…]intestinal Tract.” American Journal of Gastroenterology, December 2000. Accessed April 29, 2019.

Bolen, Barbara. “Should You Be Drinking Alcohol If You Have IBS?” Verywell Health, 2019. Accessed April 2019.

Cirino, Erica. “Why Do I Get Diarrhea After Drinking Alcohol?” Healthline, 2017. Accessed April 29, 2019.

Stephens, Carissa. “Why Alcohol Messes with Your Poop – and How to Prevent It.” Healthline, 2019. Accessed May 5, 2019.

Medical Disclaimer

The Recovery Village aims to improve the quality of life for people struggling with substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare providers.