A Dieulafoy's lesion (DL) is rare cause of acute gastrointestinal bleeding defined as a vascular abnormality of the submucosa. With a high prevalence for the stomach and upper gastrointestinal tract, it is rarely observed in the lower gastrointestinal tract. Its prevalence is rare accounting for less than 2% of all cases of acute gastrointestinal bleeding. The etiology of DL is unknown. Common comorbidities include cardiovascular disease, kidney disease, diabetes, alcohol abuse, liver disease, and chronic NSAID use. Few cases involving chronic steroid use and immunosuppressive treatment have been reported. The most common diagnostic and treatment modality is endoscopy with refractory cases treated with arterial embolization by angiography. We present a case involving a patient with significant comorbidities on chronic immunosuppression with a life-threatening, massive lower gastrointestinal bleed from a DL in the rectum.