What are the key differential diagnoses to consider in a patient presenting with symptoms of proctitis?

When a patient presents with symptoms of proctitis, key differential diagnoses to consider include infectious proctitis (caused by sexually transmitted infections such as gonorrhoea, chlamydia, herpes simplex virus, and syphilis), inflammatory bowel disease (notably ulcerative proctitis as a form of ulcerative colitis), radiation proctitis following pelvic radiotherapy, and diversion proctitis occurring after surgical diversion of the fecal stream. Other causes include ischemic proctitis, drug-induced proctitis, and less commonly, malignancy or trauma-related inflammation. Infectious causes are particularly important to consider in sexually active patients and may require targeted microbiological testing. Inflammatory bowel disease should be suspected if there is a history of chronic gastrointestinal symptoms or extraintestinal manifestations. Radiation and diversion proctitis are linked to prior treatments or surgeries. Clinical assessment combined with endoscopic evaluation and appropriate imaging or biopsy helps differentiate these conditions effectively ¹ (Wu et al., 2015; McNeil et al., 2024; Al Mulhim et al., 2021).