Spatial Orientation During Colonoscopy

Spatial Orientation During Colonoscopy

Imagine navigating the distal rectum to locate a mucosal lesion, fissure, or fistula. You identify a rectal polyp, but as you rotate the scope and retroflex, you realize you are disoriented. Where exactly is this lesion? Is it anterior, posterior, left lateral, or right lateral? Documenting the precise anatomical location of a lesion in the anorectal region is not just academic; it is critical for guiding future surgical intervention or targeted therapy. In this brief video, Dr. Klaus Mönkemüller shares a simple, high-yield trick to instantly orient yourself using a pool of water.

Anorectal Anatomy: The Orientation Challenge

When performing colonoscopy, we are accustomed to tracking our position relative to the lumen, but in the spacious anorectal vault, spatial orientation can quickly become distorted. A common mistake is relying on screen coordinates (e.g., 12 o’clock, 6 o’clock) without translating them to the patient’s actual anatomy. An endoscopy report that reads ‘polyp at 9 o’clock’ is virtually useless to a surgeon who needs to know if the lesion is anterior (near the prostate or vagina) or posterior (near the sacrum).

To solve this, use gravity rather than screen position. A small volume of water, or indigo carmine-stained water, pools dependably and shows which way is down.