A 26-year-old male with no significant medical history presented with hematochezia and was diagnosed with ulcerative colitis (UC) accompanied by immune thrombocytopenia (ITP) as an extraintestinal manifestation (EIM) of UC. This case report delves into the uncommon overlap between UC, a subtype of inflammatory bowel disease primarily affecting the colon and rectum, and ITP, an autoimmune condition leading to platelet destruction. The patient's atypical presentation and subsequent positive response to a treatment regimen targeting both UC and ITP underscores the necessity for a thorough and multifaceted diagnostic approach in individuals with UC, especially when faced with non-gastrointestinal symptoms like unexplained thrombocytopenia. The findings from this study enhance the understanding of UC's diverse manifestations and highlight its potential intersection with other autoimmune diseases, advocating for integrated care strategies in managing such intricate clinical cases.