Children may contract infection from sandboxes contaminated with petsâ stool. Certain types of immature worms may penetrate through your skin during swimming or walking barefoot; when they reach the small or large intestine they grow into adult worms. Common garden worms usually do not cause illness in human.
People with lactose intolerance do not produce enough of the lactase enzyme to break down lactose. Instead, undigested lactose sits in the gut and gets broken down by bacteria, causing gas, bloating, stomach cramps, and diarrhea. Lactose intolerance is fairly common and seems to affect guys and girls equally.
1 Lactose intolerance is caused by a deficiency of the intestinal enzyme lactase that splits lactose into two smaller sugars, glucose and galactose, and allows lactose to be absorbed from the intestine. 2  The primary symptoms of lactose intolerance are diarrhea, flatulence (passing gas), and abdominal pain.he enzyme that splits lactose into glucose and galactose is called lactase, and it is located on the surface of the cells lining the small intestine. Lactose intolerance is caused by reduced or absent activity of lactase that prevents the splitting of lactose (lactase deficiency).