The experience often called “tequila runs” is a common and unpleasant side effect of consuming the spirit. Diarrhea involves rapid, loose bowel movements resulting from chemical irritation and physiological disruption in the gastrointestinal tract. This reaction involves unique components in the tequila, the way it is consumed, and how ethanol interacts with the digestive system. Understanding these mechanisms reveals why tequila seems to provoke this response more frequently for some individuals.
How Ethanol Disrupts Digestion and Motility
The primary cause of alcohol-induced diarrhea is the direct effect of ethanol on the lining of the digestive system. Ethanol acts as a chemical irritant to the delicate mucosal lining of the stomach and intestines, triggering a defensive response. This irritation causes the muscles of the small and large intestines to contract more frequently and forcefully. The faster movement pushes the contents of the gut through the digestive tract before they can be properly processed.
This accelerated transit time is problematic because it drastically reduces the time available for the colon to perform its main function: absorbing water and electrolytes from the waste material. Alcohol also directly inhibits the colon’s ability to absorb water, a process called osmotic inhibition. As a result, the stool remains loose, watery, and is expelled quickly, which is the definition of diarrhea. Even small amounts of alcohol can initiate this cascade of irritation and motility changes in sensitive individuals.
Unique Components in Tequila That Irritate the Gut
While ethanol is the main culprit, specific compounds in tequila can amplify the gut-irritating effects. Tequila, like other distilled spirits, contains fermentation byproducts called congeners. These compounds, which include trace amounts of methanol and acetaldehyde, are considered more toxic and irritating to the gut lining. Darker or less refined tequilas, such as some Añejos or lower-quality “mixtos,” may contain higher concentrations of these congeners, intensifying the inflammation and digestive discomfort.
The type of tequila consumed introduces digestive variables related to the agave plant. True tequila is made from 100% blue agave, but lower-quality “mixto” tequilas are only required to contain 51% agave sugars. The remaining portion often comes from other sugars, such as cane sugar or high-fructose corn syrup. These non-agave sugars, along with residual agave fructans (inulin), are poorly absorbed in the small intestine. When these unabsorbed sugars reach the large intestine, they increase the osmotic load, drawing excess water into the bowel and leading to osmotic diarrhea.
The Amplifying Effect of Speed and Mixers
The way tequila is consumed, particularly the speed, significantly contributes to the digestive distress. Consuming a highly concentrated alcohol quickly overwhelms the stomach and small intestine with a large volume of irritant in a short period. This rapid concentration of ethanol intensifies the irritant effect on the intestinal lining and bypasses the body’s natural mechanisms to slow absorption. The quick influx of alcohol also causes greater osmotic stress, accelerating the entire digestive process.
Mixers commonly used with tequila introduce additional factors that exacerbate diarrhea. Many popular mixers are high in sugar, which increases the osmotic load in the intestines, drawing more water into the gut and promoting loose stools. Furthermore, carbonated beverages often used as mixers can hasten gastric emptying. This rapidly pushes the alcohol and its irritating byproducts into the small intestine, increasing the speed of the digestive upset.
Strategies for Prevention and Recovery
To minimize the likelihood of this digestive reaction, preventative strategies should be followed. Eating a solid meal containing protein and healthy fats before drinking will slow the rate of alcohol absorption, reducing the sudden shock to the digestive system. Choosing a tequila labeled “100% Agave” over a “mixto” is recommended, as pure agave versions typically have fewer irritating additives and lower congener content. Finally, alternating each alcoholic drink with a full glass of water is important for maintaining hydration and mitigating the dehydrating effect alcohol has on the colon.
If diarrhea does occur, recovery focuses on rehydration and resting the irritated gut. It is important to replenish lost fluids and electrolytes using water, broth, or sports drinks, as alcohol-induced diarrhea causes significant dehydration. Consuming bland, easily digestible foods helps to solidify the stool and soothe the intestinal lining, such as components of the BRAT diet:
- Bananas
- Rice
- Applesauce
- Toast
Over-the-counter anti-diarrheal medications can also be used to slow intestinal movement, allowing more time for water reabsorption and providing relief.