Absorption of ethanol from the small intestine into the blood takes place by passive diffusion across the intestinal cell membranes. Consequently, if someone drinks alcohol on an empty stomach the ethanol passes straight through the open pyloric sphincter into the small intestine and hence is absorbed more rapidly.
Once swallowed, a drink enters the stomach and small intestine, where small blood vessels carry it to the bloodstream. Approximately 20% of alcohol is absorbed through the stomach and most of the remaining 80% is absorbed through the small intestine.
Alcohol is absorbed throughout the digestive tract. Unlike other nutrients alcohol is absorbed directly into the blood stream through the stomach lining and it is also rapidly absorbed in the small intestine. Alcohol metabolism mostly occurs in the liver, but other cells in the body can also metabolise alcohol.
Once alcohol is swallowed, it travels down the esophagus into the stomach and the small intestine. It avoids the normal digestive process and goes right into the bloodstream. About 20 percent of the alcohol consumed is absorbed in the stomach, and about 80 percent is absorbed in the small intestine.