The belief that a bowel movement can speed up sobering up is scientifically inaccurate. Sobriety is defined by the reduction of your Blood Alcohol Concentration (BAC), which measures the alcohol in your bloodstream. Defecating does not accelerate alcohol elimination because the alcohol has already been absorbed into your circulatory system. True sobriety relies on the internal biological process of breaking down the alcohol molecule, a process that cannot be rushed by passing waste.
How the Body Processes Alcohol
The liver is the primary organ responsible for removing alcohol from the body once it enters the bloodstream. This chemical breakdown, known as metabolism, accounts for approximately 90 to 98% of all consumed alcohol. The liver treats alcohol (ethanol) as a toxin and employs specialized enzymes to neutralize it.
The initial step involves the enzyme Alcohol Dehydrogenase (ADH), which converts ethanol into the highly toxic compound acetaldehyde. A second enzyme, Aldehyde Dehydrogenase (ALDH), then breaks down the acetaldehyde into acetate, a relatively harmless substance. This acetate is eventually converted to carbon dioxide and water. The rate at which these enzymes perform this chemical conversion is largely fixed.
The liver metabolizes alcohol at a nearly constant rate, averaging a reduction of about 0.015% to 0.016% of BAC per hour. This rate is independent of factors like body size or the type of alcohol consumed. Since the liver’s enzymatic capacity is limited, consuming alcohol faster than this fixed rate causes the BAC to rise, leading to intoxication.
Actual Ways Alcohol Leaves the Body
While the vast majority of alcohol is processed through metabolic breakdown in the liver, a small percentage (2 to 10%) leaves the body unchanged through physical excretion. The primary routes for this minor elimination are the breath, the urine, and the sweat.
The measurement of alcohol in the breath is the basis of breathalyzer tests. Alcohol is a volatile substance that evaporates easily. As blood passes through the lungs, a small amount transfers into the air in the alveoli and is exhaled. Alcohol is also a diuretic, leading to increased urination, which helps eliminate some ethanol through the kidneys.
Feces play a negligible role in alcohol elimination because alcohol is rapidly absorbed into the bloodstream from the stomach and small intestine. By the time contents reach the large intestine for defecation, the vast majority of the alcohol has already been absorbed. While a bowel movement may remove any unabsorbed alcohol still in the intestinal tract, this amount is insignificant in reducing the overall circulating BAC.
Debunking the Myth and the Role of Time
The belief that using the restroom helps you sober up stems from a correlation between a temporary change in feeling and the actual reduction in BAC. Alcohol irritates the digestive tract and acts as a diuretic, making frequent bathroom use common during and after drinking. The act of getting up, walking, and focusing on a simple task can create a feeling of alertness or momentary distraction. This temporary shift in feeling is often mistaken for true sobriety.
Other common myths, such as drinking coffee, taking a cold shower, or exercising, operate on the same principle. They stimulate the central nervous system, making a person feel more awake, but they do not increase the liver’s metabolic rate. The toxic effects of alcohol remain in the bloodstream regardless of perceived alertness. The only factor that effectively lowers BAC and moves a person toward sobriety is time. Waiting allows the liver’s ADH and ALDH enzymes to complete the work of breaking down the circulating alcohol at their steady, fixed pace.