Endoanal

Endoanal is an anatomical and clinical term describing procedures and devices that access the anal canal from within, used to examine or treat conditions of the anorectal region. It encompasses imaging and physiological testing performed by inserting probes or catheters through the anal sphincter into the lower rectum. The term is used in reference to techniques that evaluate anatomy and function from inside the canal, often in proctology and colorectal practice.

Endoanal ultrasound (EAUS) uses a small, high-frequency ultrasound probe inserted into the anal canal to visualize the internal and external anal sphincters, the anorectal junction, and surrounding structures. The probe is commonly used with a water-filled balloon to improve tissue contact and image quality. EAUS provides real-time cross-sectional images that help assess sphincter integrity, detect fistulas and abscesses, and evaluate disease involvement or tumors in the anorectal region.

Endoanal manometry is another endoanal technique. It measures resting and squeeze anal canal pressures and rectal sensations with a catheter containing multiple pressure sensors. This test evaluates anal sphincter function and pelvic floor coordination, informing management of fecal incontinence and defecation disorders and aiding preoperative planning for anorectal procedures.

Practical considerations include that both techniques are generally minimally invasive with a low risk profile, but can cause discomfort or minor bleeding in some patients. They require trained operators and careful interpretation. EAUS can be limited by patient anatomy and gas but provides detailed evaluation of the anal canal and immediate surroundings; in some cases it is complemented by MRI or other imaging modalities for broader pelvic assessment. Endoanal methods enhance, rather than replace, comprehensive anorectal evaluation.