Diagnosis of large bowel tumours by colonic sonography.

To investigate whether the retrograde instillation of fluid into the colon would improve the diagnostic value of ultrasonography in assessing neoplastic diseases of the large intestine 220 patients were examined by colonic sonography before colonoscopy. Polyps larger than 7 mm diameter could be identified in 91% of cases, whereas polyps smaller than 7 mm could not always be visualised. The sensitivity of the technique in the detection of colonic carcinomas was 94% and the specificity was 100%. The results suggest that colonic sonography is an effective diagnostic procedure that may find application as a screening procedure for neoplastic diseases of the colon.