Most people who are lactose intolerant develop the condition through the natural process of aging. This is caused primary lactose intolerance. Lactose intolerance that is caused by an injury, surgery or illness is considered secondary lactose intolerance. Secondary lactose intolerance affects the stool the same way it does in all forms of lactose intolerance. Your stools can become watery, loose, explosive and foul-smelling because the lactose remains undigested in your intestines. If you notice a change in your stool, talk with your doctor because it may be a sign of another digestive condition.
Secondary Lactose Intolerance
Certain conditions, injury or illness can cause your small intestines to stop producing lactase, the enzyme required to break down lactose. Lactose is a sugar found in dairy products. After you've had viral gastroenteritis, you may notice a change in your stool after you consume dairy products. Gastric inflammatory conditions, such as Crohn's disease and celiac disease, can also affect the production of lactase. If you've recently had surgery on your intestines, you may develop temporary symptoms of lactose intolerance. Secondary lactose intolerance symptoms typically form in infancy but can develop at any age.
Stool
One of the primary symptoms of lactose intolerance is a change in your stool. If you have secondary lactose intolerance and you consume dairy products, you will notice that within the first two hours you will develop stomach cramping, pain, gas, bloating and diarrhea. You will suddenly feel like you have to have a bowel movement. During the bowl movement you will have cramping, your stool will float and it will smell foul. If you've recently been diagnosed with a digestive condition or you've had surgery, you need to report these changes in your stool to your doctor.
Cause
Your stool will only change with secondary lactose intolerance if you consume dairy products. If you have a change in your stool without consuming dairy, your symptoms are not related to secondary lactose intolerance. The reason your stool changes with this condition is because lactose cannot be absorbed by the intestines without lactase. If you don't produce enough lactase, the lactose will enter the colon undigested. The undigested lactose will interact with bacteria in the large intestine, causing the changes in your stool and the other symptoms.
Treatment
To restore normal bowel movements and regular stool you need to either remove all dairy products or take a lactase supplement before consuming products made from milk. If you eliminate all milk from your diet, you and your doctor need develop a plan to increase your daily intake of calcium and vitamin D.
