I am 20 years old female. I feel changes in my bowel habits this month. I have constipation and sometimes diarrhoea. Mucus, dark brown spot in diarrhoea. Two days I have noticed that my stool was kind of reddish in color. Previously I also saw some black diarrhoea. I get gas, heartburn, and lower abdominal pain often and pass more gas then often. I google my symptoms and it says that I may have colon cancer.