Rectal cancer and colon cancer are collectively called colorectal cancer and are one of the most common malignant tumors. Among gastrointestinal tumors, colorectal cancer is second only to gastric cancer and esophageal cancer and ranks third. The age of onset is more than 40 years old, and there are more men than women. The occurrence of colorectal cancer is related to chronic inflammation (ulcerative colitis, schistosomiasis), colorectal polyps, adenomas and certain genetic factors. In addition, people who eat high protein and high fat often have more anaerobic bacteria in the intestines, which can decompose bile acid into unsaturated polycyclic hydrocarbons, which is a carcinogen. In addition, the intake of cellulose foods is low. If the stool is stored for too long, carcinogens will accumulate, which can easily lead to colorectal cancer.
Early detection of colorectal cancer should pay special attention to the following aspects:
(1) Hematochezia is one of the early symptoms of all colorectal cancer, but the time and nature of the appearance of colorectal cancer in different parts are different. Blood in the stool is often the first symptom of patients with rectal cancer. The amount is small in the early stage, and fresh blood is often attached to one side of the stool. A small number of patients discharge more drops of fresh blood after the stool is discharged; because the sigmoid colon is closely connected to the rectum, the characteristics of blood in the stool of sigmoid colon cancer are similar to those of rectal cancer, but the color of the blood in the stool will change due to the prolonged residence time in the sigmoid colon Dark, even discharge of purple or dark purple stool, blood in the stool appears relatively late, not necessarily the first symptom of the patient. Sometimes due to low blood volume or long stay in the body, the naked eye cannot detect it, but the stool occult blood test is positive. The blood in the stool of colorectal cancer must be distinguished from the blood in the stool caused by hemorrhoids, anal fissure, bacillary dysentery, enteritis, intestinal polyps, ulcer perforation and other diseases.
(2) Changes in bowel habits include changes in the time and frequency of bowel movements, as well as constipation or unexplained diarrhea. Patients with rectal cancer may have more bowel movements, but they do not defecate much each time, or even have no stool at all. They only discharge some mucus and blood, and they have a feeling of incomplete defecation. Some patients may have diarrhea after constipation, or only the beginning of the stool is dry and the end becomes thinner, or constipation and diarrhea alternately occur.
(3) Stool with abnormally normal stool shape is cylindrical and discharged vertically from the anus. If the cancer protrudes in the rectal cavity and compresses the stool, the discharged stool strip tends to become thinner and the shape can also change. It can be flat, sometimes There is still a trace of blood attached to the deformed stool note.
(4) Some patients with diarrhea may have diarrhea as the first symptom. The patient's daily bowel movements increase, which can be mucus bloody stools, mucous thick bloody stools, or thin loose stools, which may be accompanied by tenesmus, which should be distinguished from bacillary dysentery.
(5) Pain during defecation About 50% of patients with rectal cancer have pain during defecation, ranging from mild to severe.
(6) Abdominal pain. Some patients have abdominal pain as the first or prominent symptom. Other patients show typical incomplete intestinal obstructive abdominal pain, that is, the pain is paroxysmal colic and accompanied by abdominal distension.
(7) Fatigue and anemia.