Colonic sonography: preliminary observations

Transrectal instillation of water is a recently described technique for improved sonological imaging of the lumen and wall of the colon. In order to assess the accuracy of this technique, termed colonic sonography (CS), in the detection of abnormalities of the large bowel, 100 consecutive patients were subjected to colonic sonography and the results were compared with the results of colonoscopy and surgery. The technique showed a sensitivity of 91% for the detection of colonic tuberculosis, 89% for ulcerative colitis and 83% for colonic cancers. Small mucosal ulcers, polyps less than 7 mm in diameter and the changes of non-specific colitis were not detected. Sonography displayed the entire colon more consistently than colonoscopy. The extent and extra-colonic spread of disease were better appreciated. The procedure was not adversely influenced by the presence of faecal material within the colon and was well tolerated. Colonic sonography is a promising new technique for detecting significant colonic pathology and merits further comparison with existing modalities.