With the improvement of living standard and the change of diet structure, the incidence of colon cancer is on the rise year by year. Among the clinically diagnosed colon cancer patients, about sixty percent of them have suffered from colitis. Frequent diarrhea in summer should be alert to colon cancer. For this reason, the causes of ulcerative colitis? The symptoms of ulcerative colitis? And how should ulcerative colitis be treated? About sixty percent of clinically diagnosed colon cancer patients have suffered from colitis. Among the five hundred and ninety-eight colonoscopies conducted in Xi’an Chang’an District between April and November of last year, ninety-three percent were found to have various problems, including four cases of colon cancer and thirteen percent of atypical hyperplasia, tubular adenomas and other pre-cancerous lesions. Sampling of 20,000 have frequent diarrhea physical examination, more than 95% of the colitis caused by diarrhea as a general diarrhea, casually take some medicine to stop the diarrhea will no longer be treated, as well as 3% of the diagnosed did not pay attention. Diarrhea is a common symptom of digestive system diseases, is due to the gastrointestinal secretion, digestion, absorption and motor function disorders, resulting in thin feces, the number of times, the duration of the disease more than 2 months, known as chronic diarrhea. Clinically, it is divided into: gastric diseases and intestinal contents or bile flow back into the stomach caused by diarrhea; intestinal inflammatory diseases such as bacillary dysentery, ulcerative colitis, Crohn’s disease, incomplete intestinal obstruction, tumors, dyspepsia, dysbiosis, bacterial flora, allergy to fish, shrimp, food poisoning, and some diarrhea, diarrhea caused by blood pressure medication; diarrhea caused by endocrine disorders, such as hyperthyroidism, hyperalgesia, diarrhea caused by hypogonadotropic hypoplasia; functional diarrhea, such as emotional diarrhea, intestinal diarrhea, and diarrhea. Functional diarrhea, such as emotional diarrhea, irritable bowel syndrome. Above various causes of diarrhea, the most common for a variety of intestinal infections, colon and rectal cancer, grape (coccus enterotoxin caused by food poisoning and irritable bowel syndrome. From diarrhea colitis to colon cancer there is a quantitative to qualitative process, colitis patients get colon cancer risk of up to 40%. Therefore, only by completely curing colitis, it is possible to avoid colon cancer. Colon cancer has the highest incidence rate in the age group of 40 to 60 years old. It is suggested that regular colonoscopy should be done from the age of 36 years old, especially for those who suffer from frequent diarrhea with colitis. Since colon cancer develops slowly, early symptoms can be detected through colonoscopy and can be cured without surgery.