INTRODUCTION: Mucosal prolapse is a rare condition that consists of protrusion of the rectal mucosa through the anal sphincter. This condition comprises, solitary rectal ulcer syndrome, adenocarcinoma, hamartomas, inflammatory cloacogenic polyp, inflammatory myoglandular polyp, and proctitis cystica. It is prevalent among males (3:1) and typically found in the 4-6 decades of life, the patient presents with hematochezia, tenesmus, partial incontinence, constipation, or can be asymptomatic. Surface erosion of the mucosa can occur as well as inflammation, hemorrhage, and fibrosis. Histologic features are disruption of the muscular mucosal and fibromuscular repair on the lamina propia. CASE DESCRIPTION/METHODS: The patient is a 23 year old female with a medical history of sickle cell trait and family history of gastrointestinal cancer and polyps who presented to the outpatient clinic complaining of rectal bleeding accompanied by anemia. Skin tags and large external hemorrhoids were noted on digital rectal exam (DRE). A colonoscopy was then scheduled. This was later done revealing, but was limited due to the inability to advance the scope beyond 20 cm, with evidence of a large, indurated and ulcerated mass in the rectal area measuring approximately 4 cm. Additionally a circumferential, indurated lesion 8-10 cm from anal verge was found with multiple biopsies performed to rule out malignancy (Figure 1). The biopsy results showed fragmented hyperplastic colonic mucosa showing fibrosis and smooth muscle strands in the lamina propia, consistent with mucosal prolapse syndrome (Figure 2). The patient was then referred to colorectal surgery due to hemorrhoids and prolapsed polyps near the anal verge. A hemorrhoidectomy was performed shortly thereafter for symptomatic relief. DISCUSSION: Mucosal prolapse syndrome is the presenting sign of a variety of conditions, as the differential diagnosis is broad. Among almost all cases colonoscopy will allow for direct visualization and treatment of polyps and ulcerations. Biopsies will confirm the etiology in most of the cases. These conditions present with constipation, leading to spastic contraction, which ultimately leads to congestion. Histologically, there is an overlap with the findings seen among all the mentioned etiologies. Findings such as fibromuscular obliteration, glandular crypt abnormalities, and gland dilation are reported and mimicking of adenomas and adenocarcinomas. The primary purpose is to rule out malignancy and then establish surveillance.Figure 1.: Colonoscopy showing an indurated mass in the rectal area.Figure 2.: Fragmented hyperplastic colonic mucosa showing fibrosis and smooth muscle strands in the lamina propria.