This study was performed in the population of patients with CCC whose diagnosis was not via the screening program but was merely according to the patients who have been symptomatic. In this study, the mean age was 58.91 years that was significantly lower than the developed countries [1, 11] and slightly higher than some other studies performed in our country including Fakheri et al. (52.6 years) , Jalali et al. (51.07 years)  and is somewhat similar to the study performed by Fateh et al. (56.22 years) , Semnani et al. (56 years) , and Peedikayil et al. (58.4 years) . The 25 and 50 percentile of our study were the 50 and 60 years that is different from the study of Fateh et al. (44 and 58 years) , and Jalali et al.(40 and 52 years) .
In the developed countries, only 6 to 8 percent of the patients with CCC have the age below 40 years old and only 10 percent lower than 50 years old . According to a study that surveys the race differences in the USA in 2007, the rate of CCC before 50 years is 7% in white, 12.5% in blacks, and 17.1% in the emigrants of the Pacific Asian islands . This rate is so high (23.8%) in our study that although demonstrated the more involvement of the young patients in our geographic region compared to the aforementioned studies, is lower than other studies performed in other geographic regions in our country, Iran [12, 13, 14, 18]. This difference probably can be explained as the following: either the rate of CCC in the population below 50 years old is lower in Gilan province compared to the other geographic of Iran, or there is not a suitable screening program for identifying the patients. Albeit if the second was true, the patients, have been symptomatic and recognized, ultimately, so we think the first explain should be true.
on the other hand, this high rate of disease in young patients compared to the western countries suggested the need for a good and timely screening program for this population age group.
Some explanations for the high rate of CCC in the young patients in our country can be made. First, the high rate of young population in Iran. Second, the low prevalence rate of CCC in the elderly population. Third, an absence of a suitable screening program in the high-risk population (who mainly are higher than 50 years). Fourth, the effects of environmental (raised consumption of carbohydrates and fats and low consumption of fibers) and habits (absence of sufficient mobility and obesity) factors; and fifth, probably the genetic issues.
Considering the sex difference, there was no significant difference between the two sexes that is similar to some studies [19, 20, 21]. Although some other studies reported a more prevalence of the disease in men [12–15, 22].
In opposite to the developed countries the colon cancer is two times more prevalent than rectum cancer, in our study, the rate of rectum cancer is the same or even slightly more than colon cancer, similar to reports of other developing countries [19, 23].
Considering industrialization, the difference between residents of urban and rural regions was significant. Regarding the minimal difference between the rural and urban population in Gilan province, this study demonstrated the higher prevalence of the disease in the urban region, similar to the study Fakheri et al. , and is suggestive of civilization in the higher prevalence of this disease. A study performed by You et al.  in China demonstrated the rapidly marked increase in the incidence of CCC in Shanghai; which is one of the most industrialized cities in China, and explain the relation between CCC and industrial life.
The duration of symptoms in our study was less than six months in 34.1% of patients and more than six months in 56.9%. In some studies, the mean duration was reported to the 14 weeks [25, 26, 27], but in the study by Semnani et al. , it was more than six months, too.
The most common histopathology subtype in our study was adenocarcinoma the was similar to most other studies [1, 2, 10, 12–15, 18].
Majamdar  reported that 58% of patients had left-sided involvement, but in some studies, colon cancer was more common [12, 14–16], and in some, rectum cancer was more common [13, 18, 29]. In our study, the rectosigmoid was the most common site of involvement.
The most common primary symptom was rectorrhagia in left-sided tumor and abdominal pain and mass in right-sided tumor similar to most studies performed in Iran [12–15, 18].
The percentage of right side involvement was 13.5%, that although was similar to the studies performed in our country [12–15, 18], is so lower than the study of Ashktorab et al.  performed in the USA.
According to western studies, 25% of patients with colorectal carcinoma have a familial history of the disease that 5% of them, belong to the HNPCC family and 1% to the FAP family [1, 12, 30]. In this study, 1.9% of patients had FAP, another 1.9% had a family history of CCC and 4 patients had a family history of non-CCC.
The mean age in patients with a previous history of the polyp is almost similar to the general population of the patients, which is suggestive of regular, but not accelerated course of the disease in this population. The age of affliction to the disease in the patients with FAP is so lower than the general population of the CCC, similar to the previously reported studies, and demonstrated the significance of performing the timely preventive and treatment intervention .
The mean count of the HG level was lower in the right-sided tumors, and the severity of the anemia was higher in this group of patients. This study is similar to the available results.
Surveying the patients with CCC demonstrate an increase in the number of patients in the last three years of study, which can be due to improvement to the general information and knowledge of the population regarding the importance of alarm signs of CCC.