Delayed diagnosis of colorectal sexually transmitted diseases due to their resemblance to inflammatory bowel diseases.

Objective: Sexually transmitted diseases (STDs), mainly lymphogranuloma venereum (LGV), induce colorectal symptoms that may be misdiagnosed as inflammatory bowel disease (IBD). This study describes patients who presented with STDs masquerading as IBD in order to improve understanding of missed diagnosis of colorectal STDs and their association with LGV in Israel.

Methods: This retrospective, descriptive study characterized the clinical, endoscopic, and pathological findings of 16 patients who were diagnosed with a colorectal STD after erroneously being diagnosed with IBD. Molecular genotyping was used to characterize some of the Chlamydia trachomatis isolates.

Results: All patients were men who have sex with men (MSM), mostly HIV-1-positive, and had clinical and endoscopic findings compatible with IBD. The STD was diagnosed 1-36 months after the initial diagnosis: 14 were positive for Chlamydia trachomatis, of which three were of the LGV2b (ST58) serotype and one was ST 108 serotype. Five were positive for gonorrhea and four were positive for syphilis. Several pathogens were diagnosed in six episodes.

Conclusions: Colorectal STDs may resemble IBD and therefore their diagnosis may be delayed. IBD symptoms in MSM who engage in non-protected anal sex should prompt at least syphilis and anal PCR for STD testing. If C. trachomatis is diagnosed but LGV subtyping cannot be done, doxycycline 100mg twice daily for 21days should be recommended.