Prostate cancer is the third most diagnosed cancer in men around the world, and it typically metastasizes to bone, lung, and liver. Gastrointestinal (GI) involvement by prostate cancer is rare, as patients tend to present with upper and lower GI bleed among other symptoms not related to prostate cancer, which commonly include lower urinary tract symptoms such as urinary frequency, dribbling of urine, or urinary retention. In cases of patients with prostate cancer and symptoms from the GI system, colonoscopy and biopsy of lesions should be performed to allow physicians to make an accurate and prompt diagnosis in patients with metastatic prostate cancer with rectal involvement. We present a case of a patient who initially complained of melena and was found to have a rectal nodule with biopsy-proven metastatic prostate cancer.