The inflammatory process, mediated by T cells, leads to disruption of the structure and function of the small bowel's mucous lining, and causes malabsorption as it impairs the body's ability to absorb nutrients, minerals and fat-soluble vitamins A, D, E and K from food). Lactose intolerance may be present due to the decreased bowel surface and reduced production of lactase, but typically resolves once the condition is treated.