Common symptoms of bowel cancer on the toilet include blood in the stool, abdominal pain and changes in bowel habits. Blood in stool is the earliest and most common manifestation of colorectal cancer. In mild cases, it is intermittent small amount of bleeding, while in severe cases, there may be mucus-pus-blood stool or fresh blood stool. Abdominal pain is often persistent hidden pain with inaccurate localization, and some patients only show abdominal discomfort or bloating. When colorectal cancer is secondary to infection, obvious abdominal cramps may also occur. Some patients have change of bowel habit, mostly the number of bowel movements or change of fecal character, which can be said as alternating diarrhea and constipation, and the shape of stools will also change, commonly the stools become thinner than normal. In some cases, it is accompanied by a sense of urgency (discomfort in the lower abdomen, a strong urge to relieve oneself of stool, and a feeling of incomplete evacuation afterward). If the patient has any discomfort, it is recommended to go to a regular hospital for appropriate examination and treatment under the guidance of a professional doctor.