AIM: To evaluate the accuracy of methylation of genes in stool samples for diagnosing colorectal tumours.METHODS: Electronic databases including Pub Med, Web of Science, Chinese Journal Full Text Database and Wanfang Journals Full-text Database were searched to find relevant original articles about methylated genes used in diagnosing colorectal tumours. Quality assessment of diagnostic accuracy studies items were used to evaluate the quality of the included articles, and the Meta-disc 1.4 and SPSS 13.0 software programs were used for data analysis.RESULTS: Thirty-four articles met the inclusion criteria, and 4151 patients were included. Pooled diagnostic performances of SFRP2 methylation for colorectal cancer(CRC) provided the following results: the sensitivity was 79%(95%CI: 75%-82%), the specificity was 93%(95%CI: 90%-96%), the diagnostic odds ratio(DOR) was 47.57(95%CI: 20.08-112.72), and the area under the curve was 0.9565. Additionally, the results of accuracy of SFRP2 methylation for detecting colorectal adenomas were as follows: the sensitivity was 43%(95%CI: 38%-49%), the specificity was 94%(95%CI: 91%-97%), the DOR was 11.06(95%CI: 5.77-21.18), and the area under the curve was 0.9563.CONCLUSION: Stool-based DNA testing may be useful for non-invasively diagnosing colorectal tumours, and SFRP2 methylation is a promising marker that has great potential in early CRC diagnosis. AIM: To evaluate the accuracy of methylation of genes in stool samples for diagnosed colorectal tumors. METHODS: Electronic databases including Pub Med, Web of Science, Chinese Journal Full Text Database and Wanfang Journals Full-text Database were searched to find relevant articles articles about methylated genes used in diagnosing colorectal tumors. Quality assessment of diagnostic accuracy studies items were used to evaluate the quality of the included articles, and the Meta-disc 1.4 and SPSS 13.0 software programs were used for data analysis .RESULTS: Thirty-four articles with The inclusion criteria, and 4151 patients were included. Pooled diagnostic performances of SFRP2 methylation for colorectal cancer (CRC) provided the following results: the sensitivity was 79% (95% CI: 75% -82%), the specificity was 93% ( 95% CI: 90% -96%), the diagnostic odds ratio (DOR) was 47.57 (95% CI: 20.08-112.72), and the area under the curve was 0.9565. Additionally, the results of accuracy of SFRP2 methylation for 95% CI: 91% -97%), the DOR was 11.06 (95% CI: 38% -49%) for the detection of colorectal adenomas were as follows: the sensitivity was 43% : 5.77-21.18), and the area under the curve was 0.9563. CONCLUSION: Stool-based DNA testing may be useful for non-invasively diagnosed colorectal tumors, and SFRP2 methylation is a promising marker that has great potential in early CRC diagnosis.