environmental factors associated with sporadic colorectal cancer

background: today, cancer is one of the major health problems worldwide, and the importance of this disease in our country is growing. this cancer is the third cause of death and accounts for the second largest group of non-transmissible chronic diseases. colorectal cancer is the most common gastrointestinal cancer and includes 10%  of deaths from cancer around the world. different genetic and environmental factors play a role in causing of this cancer and in this study we investigated the environmental factors associated with colorectal cancer in isfahan, iran. methods: in this case - control study, 125 patients with colorectal cancer, who had positive results by colonoscopy, were selected as case group from colorectal cancer center in isfahan (seyed al shohada hospital) and 135 people, had a negative colonoscopy results, were selected as control group,  , from the same center. cases and controls were matched by age, sex and place of residence. according to the aim of the study to investigate the cause factors of the sporadic colorectal cancer, patients who had a positive family history were excluded. extracted data included age, sex, activity, diet, consumption of nsaids, smoking and bmi. data were analyzed using a logistic regression model after entry into the spss software. findings: from the total patients studied, 9.51% were male, 1.48% female, mean age of patients was 58.32 ± 11.002. through multiple analysis, an inverse relationship was found between physical activity (or = 0.49, ci 95%: 0.34-0.7) and non-steroidal drugs (or=0.07, ci95%:0.02-0.2) with colorectal cancer. moreover, a positive association was found between dietary fat intake and colorectal cancer (or = 4.86, ci 95%: 2.96-5.45). in this study, no correlation was found between smoking and bmi with colorectal cancer. conclusion: due to the fact that  colorectal cancer is preventable and its increased incidence; educational interventions, disease screening and identifying the role of diet and physical activities in the disease appears to be necessary.