Malabsorption syndrome refers to the small intestines' inability to absorb certain nutrients and fluids. There are several common associated disorders, which may present with subtle and/or overt symptoms. With subtle symptoms, it is difficult to determine the cause, making diagnosis difficult or even inaccurate. Malabsorption can originate from an immune response, an inflammatory process, or alternation of the small intestines by surgical methods. This article reviews common malabsorption disease processes of the small bowel and the resulting pathophysiology. Diagnostic studies, treatment, and prognosis of various conditions within the malabsorption disease state are discussed.