Introduction: Gastrointestinal amyloidosis is rare in western countries. The most frequent clinical manifestation in all patients with amyloidosis is weight loss and gastrointestinal bleeding. However, diarrhea is seen in patients with secondary amyloidosis.
Case Report: A 76-year-old male presented with a six-month history of diarrhea, and had three episodes of bloody diarrhea over a two-day period prior to admission. There was associated anorexia and weight loss. Colonoscopy revealed pancolitis and a presumptive diagnosis of ulcerative colitis was made. He had resolution of his diarrhea after four days on prednisone. However, biopsy revealed colonic amyloid deposition. He also had non-nephrotic range proteinuria and cardiomyopathy and likely had systemic amyloidosis, affecting the heart and kidney in addition to colonic involvement.
Conclusion: The intestinal presentation may be similar to several conditions as a result of the protean manifestations of gastrointestinal amyloidosis. A high index of suspicion should be maintained in any patient presenting with chronic diarrhea and edema to avoid delay in diagnosis and treatment.

Keywords: Amyloidosis, Colitis, Colonoscopy, Diarrhea