Separating Infectious Proctitis from Inflammatory Bowel Disease-A Common Clinical Conundrum

Abstract

Proctitis refers to inflammation in the rectum and may result in rectal bleeding, discharge, urgency, tenesmus, and lower abdominal pain. It is a common presentation, particularly in genitourinary medicine and gastroenterology, as the two most common causes are sexually transmitted infections and inflammatory bowel disease. The incidence of infective proctitis is rising, particularly amongst high-risk groups, including men who have sex with men, those with HIV seropositive status, and those participating in high-risk sexual behaviours. The most commonly isolated organisms are Neisseria gonorrhoeae, Chlamydia trachomatis, Treponema palladium, herpes simplex virus, and Mycoplasma genitalium. Recently, proctitis was also identified as a common feature during the Mpox outbreak. Distinguishing infective proctitis from inflammatory bowel disease remains a significant clinical challenge as there is significant overlap in the clinical presentation and their endoscopic and histological features. This review compares and highlights the distinguishing hallmarks of both inflammatory and infective causes of proctitis. It provides a practical guide to describe the key features that clinicians should focus on in both clinical and key diagnostic investigations to avoid potential misdiagnosis.

Keywords: Chlamydia trachomatis; Mpox; Neisseria gonorrhoeae; inflammatory bowel disease; lymphogranuloma venereum; proctitis; sexually transmitted infection.

Figure 1

Endoscopic features of infective proctitis. (A,B): Neisseria gonorrhoeae causing mucosal oedema, erythema, white plaques, (A) and superficial erosions (B). (C,D): Chlamydia trachomatis lymphogranuloma venereum serovars causing multiple nodules with central ulceration with surrounding oedema and erythema, (C) and a large ulcer in the distal rectum with surrounding friable mucosa (D). (E,F): Treponema pallidum causing ulceration with polypoid hyperaemic lesions (E) and a friable ulcerated rectal mass (F). (G,H): Herpes simplex virus causing erythematous and friable mucosa (G) with ulceration and mucopurulent discharge (H). (I): Mpox causing severe proctitis with ulceration with pustular lesions. All images reproduced and adapted with permissions. All copyrights remain with the original copyright holders. (A): Sigle and Kim [53] © Georg Thieme Verlag KG with permission. (B): Coelho et al. [46] ©Hellenic Society of Gastroenterology. Licence under CC-BY-NC 4.0. (C): Law et al. [59] © 2020, the AGA Institute with permission from Elsevier. (D): Di Altobrando et al. [60] © Crohn’s & Colitis Foundation. Licence under CC-BY-NC 4.0. (E): You et al. [61] © The Korean Journal of Gastroenterology. Licence under CC BY-NC 3.0. (F): Costales-Cantrell et al. [62] © 2021 Society of General Internal Medicine, with permission from Springer Nature. (G,H): Sandgren et al. [63] © 2017. Licence under CC-BY 4.0. (I): Mavilia et al. [64] © 2023 the AGA Institute, with permission from Elsevier.

Figure 2

Suggested flow chart to distinguish infective proctitis from inflammatory proctitis. MSM, men who have sex with men; IBD, inflammatory bowel disease; NG, Neisseria gonorrhoeae; CT, Chlamydia trachomatis; LGV, Lymphogranuloma venereum; TP, Treponema pallidum; HSV, herpes simplex virus; MG, Mycoplasma genitalium. ¹ UK guidelines recommend empirical treatment to cover NG, CT (including LGV) and HSV for patient with and probable sexually transmitted proctitis and severe symptoms (Richardson et al. [140]).