Lactose is unabsorbable and increases the osmotic gradient within the small intestine.
This produces a net flow of water and electrolytes into the small intestine. Symptoms Because of the increased volume of bowel gas and water, as well as the decreased intestinal transit time produced by the increased small intestinal water and solute load, patients may develop abdominal pain and bloating, distension, borborygmi, diarrhea, and flatulence. Types Intestinal lactase activity varies by age and ethnic origin. Adult lactase deficiency. Inherited as an autosomal recessive trait.