Preparation Stool tagging

However bowel preparation should be tailored to the indication, with full or reduced cathartic preparation associated to tagging of fluids or stool. Adequate colonic distension (pneumocolon) is cru-dal for identification of colorectal polyps and differentiation between obstructive cancers and a collapsed segment. Distension is achieved by rectal air or carbon-dioxide insufflation, and standard scout view in lateral and anterior-posterior projections are acquired to verify the distension of the entire colon. The intravenous administration of a muscle rdaxant, to reduce large bowel movement and... 

This preparation is routinely used at our institution in all patients referred for screening for colorectal cancer, change in bowel habit, iron deficiency anaemia, constipation, heme positive stool, etc. (see Chap. 2). Intravenous contrast is never used as the polyps may enhance and simulate tagged stool causing a false negative finding. 

Mostly this non-tagged stool does not cause any diagnostic problems. In a recent study of 180 patients (Lefere et al. 2005) using this preparation no false positives were caused by non-tagged stool (see Sect. 4.6, Results). 

Faecal residue with a foamy appearance is mostly detected in the cecum or ascending colon. It appears as an amorphous inhomogeneous mixture mostly of air bubbles and stool. They occur in both preparations without and with faecal tagging. In the latter case the foam is tagged or non-tagged. This foam may distract the reader s attention or cover a lesion making detection difficult (Fig 4.19). 

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