Malabsorption is a digestive disorder that prevents the body from effectively absorbing nutrients from food. There are many causes of malabsorption, including damage to the mucous lining of the small intestine, where most absorption happens. Some of the other causes of malabsorption include:

• Insufficient production of digestive enzymes by the pancreas, which occurs with some pancreatic diseases, or by the small intestine, which occurs in lactase deficiency
• Cystic fibrosis, which is the number one cause of malabsorption in the United States
• Chronic pancreatitis, infections or swelling of the pancreas, trauma to the pancreas, or surgery to remove part of the pancreas
• AIDS and HIV
• Celiac disease
• Whipple disease
• Short bowel syndrome (SBS), which is a condition where the small intestine is shortened, making it less able to absorb nutrients
• Tropical sprue, which is a condition most common in the Caribbean, India, and parts of Southeast Asia

Malabsorption can lead to indigestion and even malnutrition, not from a lack of eating enough nutrients, but from an inability to absorb them. Symptoms of malabsorption include diarrhea, weight loss, and bulky, foul-smelling stools. The diagnosis is based on typical symptoms, along with stool tests and sometimes a biopsy of the lining of the small intestine. The treatment depends on the cause, and may include a special diet of foods that are more easily digested and absorbed, as well as supplements to make up for nutrients that aren’t being absorbed well.