Recent developments in the role of endoscopic ultrasonography in diseases of the colon and rectum.

PURPOSE OF REVIEW Endoscopic ultrasound has evolved as a useful technique for imaging and intervention in a variety of gastrointestinal and extraintestinal diseases including diseases of the colon and rectum. This paper will review recent developments in endoscopic ultrasound for colorectal diseases. RECENT FINDINGS Recent studies have shown significant clinical impact of endoscopic ultrasound in rectal cancer staging. Iliac lymph node evaluation by endoscopic ultrasound-guided fine needle aspiration may further expand the role of endoscopic ultrasound in rectal cancer. Three-dimensional endoscopic ultrasound may help decrease some of the errors of staging with two-dimensional endoscopic ultrasound and may further improve staging accuracy. Recent studies have confirmed continued problems with re-staging rectal cancer after chemoradiation. Endoscopic ultrasound-fine needle aspiration can be helpful in detecting local recurrence of rectal cancer and has been shown to be useful in evaluation of subepithelial masses of the colon and rectum and evaluation of rectosigmoid endometriosis. SUMMARY Endoscopic ultrasound continues to be useful for a variety of conditions of the colon and rectum with recent studies confirming its clinical impact as well as expanding its role into newer indications. Assessment for residual cancer after chemoradiation is still problematic and hopefully technological developments in ultrasound in the future may help in improving the accuracy of endoscopic ultrasound in this situation.