There are quite a few alternatives to barium enemas, the best known of which is colonoscopy. This involves passing a fibreoptic cable up into the colon to view the colonic wall. Colonoscopy is now rapidly supplanting barium enemas as a screening test for colon cancer. It is considered to be both more accurate (about 90 per cent) and easier for the patient, although it is more expensive and has a higher complication rate (Clin Radiol, 2001; 56: 401-9).

CT (computed tomography) scans and MRI (magnetic resonance imaging) are beginning to be used, but their accuracy is a relatively unimpressive 70 per cent (Radiol Clin North Am, 1997; 35: 457-85). CT scans also tend to give a high radiation dose (Scand J Surg, 2002; 91: 322-7). Ultrasound has an overall 85 per cent accuracy (Aliment Pharmacol Ther, 2003; 18: 1009-16), but may be poor at detecting cancer; endoscopic ultrasound has a better record, however (Gastrointest Endosc, 1993; 39: 521-7). In the near future, computed tomographic colography and magnetic endoscopic imaging promise greater accuracy and ease of use (Can J Gastroenterol, 2003; 17: 125-8; Endoscopy, 2002; 34: 900-4).

Today, however, the whole field of colonic imaging remains in disarray, with the US government’s recent task force on colon-cancer screening unable to recommend any one technique over another (Ann Intern Med, 2002; 137: 1-38). Nevertheless, if you want to avoid contrast media or high doses of X-rays, it may be prudent to investigate the alternatives to barium enema.