Abdominal pain, cramping and chills, accompanied by loose watery stools that occur several times a day, combined with a persistent urge to use the bathroom, are all symptoms indicative of diarrhea. If you experience these symptoms after eating yogurt, it could mean that your body's immune system is having an abnormal reaction to the phosphoproteins in the yogurt.
The Basics
Yogurt is a cultured version of cream, milk, skim milk or a combination of these ingredients. Yogurt manufacturers inoculate the milk product with Lactobacillus bulgaricus or Streptococcus thermophiles, both lactic acid-producing bacteria. Once inoculated, incubation at a temperature of approximately 110 degrees Fahrenheit firms up the yogurt. According to Oklahoma State University Extension, cow's milk is the base for most yogurts in the U.S., but in other countries, yogurt is a derivative of goat, yak, horse or sheep's milk.
Casein Allergy
Casein is a protein found in mammal milk. For some people, casein proteins cause an allergic response inside the body that results in a series of uncomfortable symptoms, including diarrhea. According to Clemson University Cooperative Extension Service, if you have a milk allergy, you should avoid all forms of milk, cheese, butter, ice cream, pudding, custard, whey and yogurt. Aside from diarrhea, ingesting these foods might also cause hives, swelling, sinus congestion, difficulty breathing, cramps, nausea, vomiting and in severe cases anaphylaxis -- a life-threatening allergic reaction in which breathing gets blocked or limited from throat and mouth swelling, requiring immediate medical attention.
Misconceptions
Lactose intolerance, or the inability to digest milk sugars, is another problem associated with dairy products. Although lactose intolerance has similar symptoms, which include diarrhea, it is not an allergy. In fact, if you are lactose intolerant, it is more than likely that you will have no problem tolerating fermented milk products such as yogurt. Ohio State University says the bacteria in yogurt break up the lactose, making it easier to digest. Lactobacillus bulgaricus and Streptococcus thermophiles do not break down casein.
Alternatives
If you love yogurt, but suffer diarrhea when you consume it, alternatives are available. Rice and soy yogurts are not only lactose-free, but also casein free, which is good news for anyone who suffers from milk allergies. Available online, in health food stores and in your grocery store's refrigerated section, rice and soy yogurts tend to be pricier than traditional yogurt. While the look and texture of these yogurts is similar to milk-based yogurt, the taste is not identical, so you might need to get used to them.
