Natural sugars within milk and dairy products are known as lactose. Lactose intolerance is a condition that causes the inability to process the lactose within dairy products. This occurs when the body does not produce the enzyme (lactase) that is needed to break down and process the lactose in dairy.

While lactose intolerance can cause discomfort, it isn’t life threatening like a milk allergy. Symptoms of lactose intolerance may include the following signs and symptoms:

1. Stomach pain and cramps
Stomach pain is something that is common with lactose intolerance. Undigested lactose will settle in the colon, and begin to ferment. This can cause pain to develop near the naval area and lower stomach area. The fermentation happens because the colon is unable to absorb the lactose, but the bacteria that exist naturally will start to break it down. The level of stomach pain that one feels is dependent on the level of one’s pain tolerance when the distention from fermentation begins. Cramps are the primary manifestation of stomach pain. Cramps related to lactose intolerance feel like sharp pains and do not feel like menstrual cramps.

2. Gas and bloating
Similar to stomach pain, gas and bloating will occur when fermentation of lactose occurs in the colon. When this happens, gases including methane, carbon dioxide, and hydrogen are released into the body. Bloating is not directly correlated with the amount of lactose that a lactose intolerant individual consumes. It is connected to how much distention someone can handle. So if an individual’s body is not distressed by the bloating caused by the fermentation, then it will be less noticeable to that individual.

3. Diarrhea or loose stools
Diarrhea is defined as a passing of seven ounces of stool in a 24 hour period. Lactose intolerance can cause an excess of water in the colon, which will lead to more water in the stool. However, this is more common with younger people rather than adults. When the fermentation process occurs in the colon, acids are released. Most are reabsorbed, but the acids that are not lead to the increased water in the colon which results in diarrhea and loose stools.

4. Constipation
This is less common than diarrhea. It is when someone does not have consistent or complete bowel movements, and it can also result in hard stools. One of the gases that are released during the fermentation process is methane. Methane can slow down food being processed which can lead to the symptom. Methane is more directly connected with irritable bowel syndrome when it comes to constipation, but it still can lead to the symptom when someone is lactose intolerant.

5. Mouth ulcers
These are also known as canker sores and are connected to symptoms of lactose intolerance. However, they are one of the minor symptoms that occur, but it’s not necessarily due to lactose intolerance. Mouth ulcers can be connected to a dairy allergy, which many people mistake as lactose intolerance. However, a dairy allergy is typically accompanied by more serious symptoms such as hives, red flushing, swelling of the tongue, lips and throat, and in serious cases, anaphylaxis.