Which symptoms are common in individuals with lactose intolerance?

Individuals with lactose intolerance commonly experience symptoms such as cramps, flatus (gas), and osmotic diarrhea. This condition arises due to the body's inability to properly digest lactose, a sugar found in milk and dairy products. When lactose is consumed, it may not be adequately broken down in the small intestine due to a deficiency in the enzyme lactase. As a result, undigested lactose moves into the colon, where gut bacteria ferment it, leading to excessive gas production (flatus) and attracting water into the intestines, which can cause osmotic diarrhea. The abdominal cramps result from the increased gas and fluid in the bowel.

The other symptoms presented in the other options don't align with the typical presentation of lactose intolerance. Symptoms like nausea, vomiting, and headache can occur in various gastrointestinal disorders but are not specific to lactose intolerance. Dizziness, fatigue, and muscle pain are more general symptoms associated with a variety of conditions, not specifically linked to lactose digestion. Lastly, constipation, bloating, and rash could be associated with other digestive issues or food intolerances but are not the primary symptoms associated with lactose intolerance.