Beer does not cause diarrhea in healthy adults. Certain ingredients may cause an allergic reaction in some people that results in diarrhea. The Auckland Allergy Clinic states that barley, hops and yeast may be the cause of some allergic reactions to beer. Beer is made from wheat byproducts and can cause an allergic reaction in people who are allergic to wheat. Stop drinking beer if you develop diarrhea until you can be seen by a doctor.
Diarrhea from drinking beer is the result of inflammation in the digestive system from increased levels of histamine. If you're allergic to one or more of the ingredients in beer, your immune system overreacts to the substance and begins to defend the body by creating immunoglobulin E, or IgE, antibodies. IgE antibodies cause mast cells to produce histamine to help defend the body, according to MayoClinic.com. Histamine is a chemical in the body that protects the body from infection. Too much histamine causes swelling, inflammation and irritation in soft tissue.
If you're allergic to ingredients in beer, you will develop symptoms within a few minutes of ingesting the beverage. Some of the first symptoms may include gastric symptoms, such as gas, bloating, nausea, vomiting, cramping and diarrhea. Once the allergen is expelled from the body, your symptoms will subside. If diarrhea continues for more than a day, you need to seek medical attention. Other symptoms of an allergic reaction to beer may include skin rashes, facial swelling, nasal congestion and asthma.
Diarrhea from drinking beer may be a sign of gluten intolerance, or celiac disease. Celiac disease is a common condition where gluten, a protein in wheat, causes damage to your small intestines. The cause of this condition is uncertain, but it will result in stomach pain, bloating and diarrhea, according to the National Digestive Diseases Information Clearinghouse. If you are diagnosed with gluten intolerance, you need to avoid all foods and beverages that contain gluten, including beer.
If you're allergic to wheat, do not drink beer. A severe allergic reaction can occur, leaving you at risk of serious complications. Anaphylaxis is an extreme allergic reaction that can restrict your ability to breathe normally, potentially leading to death. Diarrhea is a sign of anaphylaxis. If you suspect that you're experiencing this type of allergic reaction, call 911 for immediate attention.