Endoanal ultrasound is a type of medical investigation which uses

ultrasonography Medical ultrasound includes diagnostic techniques (mainly imaging) using ultrasound, as well as therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal body structures such as tendons, muscles, joints, ...

to show images of the structures of the

anal canal The anal canal is the part that connects the rectum to the anus, located below the level of the pelvic diaphragm. It is located within the anal triangle of the perineum, between the right and left ischioanal fossa. As the final functional s ...

. It is used in the investigation of some anorectal symptoms, e.g.

fecal incontinence Fecal incontinence (FI), or in some forms, encopresis, is a lack of control over defecation, leading to involuntary loss of bowel contents—including flatus (gas), liquid stool elements and mucus, or solid feces. FI is a sign or a symptom ...

obstructed defecation Obstructed defecation syndrome (abbreviated as ODS, with many synonymous terms) is a major cause of functional constipation (primary constipation), of which it is considered a subtype. It is characterized by difficult and/or incomplete emptying ...

. Endorectal ultrasound is a similar investigation but the ultrasound probe is used to image the rectum and surrounding tissues. It is used to image lesions in the rectum, for example a tumor caused by

colorectal cancer Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the Colon (anatomy), colon or rectum (parts of the large intestine). Signs and symptoms may include Lower gastrointestinal ...

and to assess local lymph node involvement.

References

Colorectal surgery Diagnostic medical imaging Digestive system imaging Gastroenterology Medical ultrasonography {{med-imaging-stub