Steatorrhea is the passage of bulky offensive stools, they are characteristically difficult to flush down the toilet (fat floats).
Fat is broken down by Lipases (eg from the pancreas) and because of the fact the fats are not soluble in water they have to be solubulised with bile salts from bile. Lack of Lipase (eg exocrine pancreatic insufficiency in chronic pancreatitis) results in steatorrhoea. Similarly lack of bile salts will result in steatorrhoea. Overgrowth of bacteria in the residual bowel may result in deconjugation of any remaining conjugated bile salts so that they loose their ability to form micelles.
Patients who cannot absorb fat well will soon run out of fat soluble vitamins, these are D, E, K and A.
Essential fatty acids may become deficient in the longer term and may need to be supplemented. Essential fatty acid deficiency is often first manifest as an obscure rash.