Malabsorption syndromes are disorders due to a deficiency in the absorption of nutrients from the small intestine into the bloodstream. Normally, food is digested and the nutrients necessary for the proper functioning of the body are absorbed into the bloodstream from the small intestine. Malabsorption can occur due to either a disorder which interferes with normal food digestion or due to a disorder that directly effects the mechanism of absorption.

• Disorders that interfere with digestion .
  Disorders that result in too much or too little stomach acid to digest food or disorders which result in inadequate amounts of enzymes necessary for breaking down ingested foods (e.g. Pancreatitis, Cystic fibrosis, Lactase deficiency, Obstruction of the bile duct) are the most common types of disorder that interfere with digestion, resulting in malabsorption.
  
  
• Disorders that effect the mechanisms of absorption .
  Infections, drugs (e.g. Neomycin, alcohol), Celiac disease and Crohn's disease all injure the sensitive stomach lining and thus decrease the area available for adequate absorption of nutrients. Lymphoma and an inadequate blood supply to the intestine are examples of disorders that prevent substances from being passed into the bloodstream.

Symptoms of malabsorption include weight loss, malnutrition (due to a lack of essential minerals and vitaines), diarrhea, abdominal bloating, flatulence, jaundice and steatorrhea (light-coloured, foul-smelling stool that may float and stick to the side of the toilet bowel). These symptoms, of course, vary according to the precise disorder in question.

Treatment may include avoidance of certain substances (e.g. Lactose in lactose intolerance), antibiotics (where the cause is an infection) or a simple change in diet.