Amyloidosis, a heterogeneous group of disorders, is characterized by the extracellular deposition of misfolded, insoluble, fibrillar proteins. These extracellular proteins deposit in tissues, aggregate into symmetrically arranged pleated sheets, and cause distortion of tissue structure and function.

high degree of clinical suspicion is required to make a definitive diagnosis of gastrointestinal amyloidosis. Because of the rarity of the condition and the nonspecific signs and symptoms at presentation, these patients often undergo extensive and unnecessary testing to determine the cause of their clinical presentation.

Amyloidosis is characterized by extracellular deposition of abnormal proteins, including primary, secondary, hemodialysis-associated, hereditary, and focal types. Primary amyloidosis is divided into monoclonal light chain-associated amyloidosis. Secondary amyloidosis is associated with inflammatory, infectious, and neoplastic diseases. Amyloid deposition in the gastrointestinal tract may manifest as symptoms including diarrhea, dysuria, or constipation.

In 1853, Rudolf Virchow first used the term “amyloid” to describe deposits in the brain that closely resembled starch after they were stained with iodine and sulfuric acid. Amyloidosis comprises a heterogeneous group of disorders characterized by extracellular deposition of fibrillar fibers that aggregate into a three-dimensional ß-lamina (anti-patterned sheet) in tissues, disrupting normal tissue structure and function.