Non-laxative CT colonography with barium-based faecal tagging: is additional phosphate enema beneficial and well tolerated?
OBJECTIVE
The purpose of this study was to investigate the efficacy and tolerance of an additional phosphate enema prior to non-laxative CT colonography (CTC).


METHODS
71 patients (mean age 80 years, 28 male, 43 female) underwent non-laxative CTC following 4 oral doses of diluted 2% w/w barium sulphate. Patients were invited to self-administer a phosphate enema 2 h before CTC. An experienced observer graded the volume of retained stool (1 (nil) to 4 (>75% bowel circumference coated)), retained fluid ((1 (nil) to 4 (>50% circumference obscured)), retained stool tagging quality (1 (untagged) to 5 (≥75% to 100%) tagged) and confidence a polyp ≥6 mm could be excluded (yes/no) for each of six colonic segments. Tolerance of the enema was assessed via questionnaire. Data were analysed between those using and not using the enema by Mann-Whitney and Fisher's exact test. 18/71 patients declined the enema.


RESULTS
There was no reduction in residual stool volume with enema use compared with non-use either overall (mean score 2.6 vs 2.7, p = 0.76) or in the left colon (mean 2.3 vs 2.4, p = 0.47). Overall tagging quality was no different (mean score 4.4 vs 4.3, p = 0.43). There was significantly more retained left colonic fluid post enema (mean score 1.9 vs 1.1, p<0.0001), and diagnostic confidence in excluding polyps was significantly reduced (exclusion not possible in 35% segments vs 21% without enema, p = 0.006). Of 53 patients, 30 (56%) found the enema straightforward to use, but 4 (8%) found it unpleasant.


CONCLUSIONS
Phosphate enema use prior to non-laxative CTC leads to greater retained fluid, reducing diagnostic confidence, and is not recommended.
Department of Specialist Radiology, University College Hospital, London, UK.
W
W
Davis
P
P
Nisbet
C
C
Hare
P
P
Cooke
S A
SA
Taylor
D000368:Aged; D000369:Aged, 80 and over; D001466:Barium Sulfate; D002400:Cathartics / Q000008:administration & dosage*; D023881:Colonography, Computed Tomographic / Q000379:methods*; D003287:Contrast Media; D004733:Enema / Q000009:adverse effects* / Q000379:methods; D005243:Feces; D005260:Female; D006801:Humans; D008297:Male; D017060:Patient Satisfaction; D011795:Surveys and Questionnaires
D002400:Cathartics; D003287:Contrast Media; D001466:Barium Sulfate