Background: The diagnostic value of a positive fecal occult blood test (FOBT) at the time of digital rectal examination (DRE) is disputed despite being used commonly by a significant number of physicians. A meta-analysis was conducted to evaluate FOBT by DRE for detecting neoplasia versus FOBT on stool passed spontaneously (SPS) in asymptomatic patients undergoing colorectal cancer screening.
Methods: MEDLINE, the Cochrane Central Register of Controlled Trials and the Cochrane database of systematic reviews, CINAHL, PubMed, and recent abstracts from major conferences were searched in August 2011. We included all of the studies that compared stool sampling techniques for FOBT. Separate analyses were performed for each main outcome (normal, nonadvanced adenoma, advanced adenoma, and colon cancer).
Results: Seven studies (N = 1835) met the inclusion criteria. The use of DRE for FOBT demonstrated statistically significant fewer advanced adenomas than SPS for FOBT. No statistically significant differences were noted for normal findings, neoplasia, nonadvanced adenoma, or colon cancer with DRE compared with SPS for FOBT.
Conclusions: DRE for FOBT appears to be less effective at detecting advanced adenomas as compared with SPS despite cancer detection being similar. FOBT by SPS appears to be statistically superior to FOBT by DRE.