A 52-year-old male, without significant past medical history, is referred for new onset constipation, hematochezia and significant weight loss. Blood tests were unremarkable. A colonoscopy was performed, showing reddish, hematocystic and friable mucosa in a circumferential pattern in the rectum, with similar patches throughout the whole colon, one of them infiltrating the ileocecal valve. Biopsies were obtained and revealed spindle cell proliferation immunoreactive for CD34 and herpesvirus 8 (HHV-8), compatible with Kaposi's sarcoma (KS). HIV serologies were subsequently done, with a positive result, the patient then reporting previous heterosexual unprotected sexual activities. He was started on highly active antiretroviral therapy (HAART) and chemotherapy with liposomal doxorubicin, with a favorable outcome to this date. KS is a low-grade tumor of the vascular endothelium that requires infection with HHV-8. HIV-related KS is more commonly diagnosed in homosexual males with uncontrolled HIV infection and is associated with a variable clinical course. The gastrointestinal tract is involved in up to 51% of patients, but since the majority is clinically silent (70%), visceral involvement is probably underestimated. The treatment goal is symptomatic relief, and may range from HAART alone to a combination with systemic chemotherapy, depending on disease extent. We present this case given its endoscopic exuberance, with biopsies showing an HIV-defining condition, in a patient unaware of his diagnosis.