[Endoscopic ultrasound in the lower gastrointestinal tract].

Endoscopic ultrasound is a minimally invasive modality that combines endoscopy with ultrasound, providing a possibility to visualize the wall of the gastrointestinal tract and adjacent tissues and organs. Since the development of the modality in the 1980s, advancements in endoscopic ultrasound technology have led to increasingly broadening indications: besides diagnostic indications, therapeutic indications have also expanded greatly. According to recent guidelines regarding rectal cancer staging, rectal ultrasonography is mainly considered to be a secondary imaging modality compared to magnetic resonance imaging. With the use of forward-viewing echoendoscopes and ultrasound miniprobes that can be inserted through the working channel of the endoscope, endoscopic ultrasound technology can be expanded to proximal, colonic areas as well. Rectal ultrasonography can also play an important role in the differential diagnosis of subepithelial lesions, in the detection of rectal varices, in the diagnosis of inflammatory bowel diseases as well as perianal complications. Diagnostic accuracy can further be improved with the addition of ultrasound-guided sampling in certain cases. Currently, therapeutic indications are more like promising possibilities, than part of everyday clinical practice, but this might change in the near future. The purpose of this review is to summarize the current indications of rectal ultrasound in the clinical practice, including diagnostic and therapeutic ones as well. Orv Hetil. 2023; 164(30): 1176-1186.