Sigmoid Diverticulitis: Value of transrectal sonography in addition to transabdominal sonography

OBJECTIVE. Overlying intestinal gas often impairs transabdominal sonographi c assessment of the lower sigmoid colon. The aim of this study was to inves tigate the usefulness of transrectal sonography in addition to transabdomin al sonography for the evaluation of sigmoid diverticulitis. SUBJECTS AND METHODS. Eighty-six consecutive patients with clinically suspe cted acute sigmoid diverticulitis were referred for transabdominal sonograp hy as the initial imagine, method. In 46 patients, transrectal sonography w as performed in addition to transabdominal sonography if pain was localized to the mid lower abdomen and if a disease process could not be visualized or could be only partially visualized on transabdominal examination. An end -firing 5-9-MHz endocavitary probe was used for transrectal sonography. RESULTS, Thirty-four of 50 patients with a final diagnosis of sigmoid diver ticulitis underwent both transabdominal and transrectal sonography. In 20 p atients, transrectal sonography showed relevant additional information: six diagnoses of diverticulitis were established on transrectal sonography alo ne. Transrectal sonography revealed one perforation, five abscesses, and th ree fistulous complications that were not shown on transabdominal sonograph y. In the remaining five patients, correct diagnoses were supported on tran sabdominal examinations, but only transrectal sonography could show an infl amed diverticulum. In 10 patients, transrectal sonography revealed signs of diverticulitis but no relevant information in addition to the results from transabdominal sonography. Four false-negative and two false-positive resu lts were revealed with transrectal sonography. CONCLUSION, Transrectal sonography is accurate for confirming clinically su spected acute colonic diverticulitis when the lower sigmoid colon is affect ed. It helps avoid false-negative results and defines the severity of disea se in the lower sigmoid colon better than transabdominal sonography alone. Transrectal sonography can increase the sensitivity of sonography for diagn osing sigmoid diverticulitis.