Lactose intolerance describes a digestive condition in which the body fails to produce the enzyme lactase that breaks down lactose so the body can absorb it. Lactose intolerance can occur due to a congenital defect, injury to the small intestines or as a normal part of aging, according to the Mayo Clinic. Lactose intolerance causes symptoms similar to irritable bowel syndrome---IBS, a functional digestive disorder that affects approximately 20 percent of all Americans in the United States, according to the National Digestive Diseases Information Clearinghouse.
Abdominal Cramps
The abdominal region contains many organs in the body, including the digestive organs,spleen, appendix and kidneys. Although abdominal pain may occur due to many different conditions affecting any one of these organs, cramp-like pain most commonly occurs as a result of digestive problems that cause gas and bloating, according to MedLine Plus and the National Institutes of Health. In IBS, abdominal cramps occur because the intestines fail to contract normally. This causes food content to move either too fast or too slow through the intestines. Either way, the muscles lining the intestines produce cramp-like pain. In lactose intolerance, the lactose remains intact, which causes a build-up of gas resulting in cramping abdominal pain.
Bloating and Gas
Passing gas can be embarrassing, but the fact is that all people produce intestinal gas. Most people produce between one and four pints of gas a day resulting in the passing of gas, either through the rectum or through burping, about 14 times a day, according to the National Digestive Diseases Information Clearinghouse. Gas occurs when the bacteria in the large intestines break down food particles that fail to get digested in the small intestines.
Those who suffer from lactose intolerance do not produce enough lactase to break down the lactose, so it continues on into the large intestines. The bacteria in the large intestine break it down and produce hydrogen, carbon dioxide and methane gases in the process. Those with IBS suffer from excess gas because food moves too quickly through the small intestines and enters the large intestines without getting completely broken down. An excess of gas causes abdominal bloating, or a feeling of fullness.
Diarrhea
Doctors use the term "diarrhea" to describe loose, watery stools that occur more frequently than normal. Diarrhea can occur as a result of many conditions, including bacterial infections, viral infections and parasites, but the most common causes include food intolerances and functional bowel disorder, or IBS. When the body fails to digest and absorb lactose, it continues to travel through the lower digestive tract, triggering diarrhea. IBS causes diarrhea because, when food contents travel too quickly through the intestines, the body cannot absorb the water from the stools, therefore resulting in diarrhea.
