Rectum

The rectum is the terminal segment of the large intestine, typically measuring between 12 and 15 cm in length, and serves as a temporary reservoir for feces before defecation [1, 2]. It is characterized by its role in the defecation reflex, where the stretching of the rectal walls signals the nervous system to initiate the urge to evacuate [1, 3]. While the rectum itself is an anatomical organ and not a specific molecular target, it is a primary site for significant diseases such as colorectal cancer and inflammatory bowel diseases like ulcerative proctitis [4]. In pharmacology, the rectum is a vital route for drug administration, particularly when oral intake is not possible or when localized treatment of the rectal mucosa is required [5]. Therapeutic agents such as mesalamine or corticosteroids are often delivered rectally to manage inflammation by interacting with molecular pathways within the intestinal lining [5].

Other names

Terminal large intestineRectal canalRectal vault

Not applicable. The rectum is an anatomical organ rather than a molecular target; however, drugs administered to the rectum typically target inflammatory mediators (e.g., TNF-alpha) or provide local anesthesia by blocking sodium channels [1, 5].