Colorectal cancer is a common tumor that seriously threatens human health and life. It is the most common malignant tumor in developed countries such as Western Europe and North America. It ranks fourth in China and has a recent upward trend. Rectal cancer accounts for more than half of colorectal cancers. At present, the treatment of malignant tumors is still based on surgical resection. The early detection of rectal cancer is clinically important. It will not only affect the success rate of surgical resection, but also has a close relationship with the prognosis (recurrence rate and survival rate after surgery). How to detect rectal cancer early is particularly important.
The most common clinical symptom of rectal cancer is blood in the stool, usually dark red or bright red. It contains mucus or pus, and sometimes a blood clot. It is often misdiagnosed as hemorrhoids and delayed treatment, which aggravates the condition. Most of the patients who come to the clinic are in the middle and late stages, and the treatment is very difficult. Bleeding from hemorrhoids is mostly bright red. The bleeding is usually dripped or ejected after defecation, and the blood does not mix with the stool; while the bleeding from rectal cancer is mostly mixed with the stool and accompanied by foul smell.
Another symptom of rectal cancer is the change of bowel habits. Early rectal cancer shows increased stool frequency, loose stools or mucous stools, or anal swelling and discomfort, and incomplete defecation. The stool frequency is several to ten times a day, and the stool volume is reduced, mostly mucus or pus. After the tumor is enlarged, stool may become thinner, deformed, and difficult to defecate. Mucus, bloody stools and anal swelling can easily be misdiagnosed as dysentery or other intestinal inflammatory diseases.
Rectal cancer further develops. Anal pain occurs when it invades the skin of the anal canal; when it invades the sacral sacral plexus, there is severe and continuous pain in the rectum or sacrococcyx, which radiates to the waist, perineum, or the inner side of the lower limbs. When the tumor grows, it blocks the intestines and causes obstruction. Long-term bleeding causes anemia, and dyscrasias appear in the late stage.
If you have the symptoms mentioned above, you should seek medical treatment immediately and have a thorough and careful examination. The commonly used examination methods are mainly as follows.
1. Digital rectal examination: Digital rectal examination is a simple and extremely effective method for the diagnosis of tumors in the middle and lower rectum. In clinical practice, many doctors ignore digital rectal examination and misdiagnose. The lateral position or the thoracic-knee position is usually used, and the position about 7 to 8 cm away from the anal margin is generally palpable, and 70% of rectal masses can be palpated by digital examination. Through digital examination, you can find the location, size, shape, texture, whether there is a pedicle, the activity of the base, the depth of tumor infiltration, and the relationship between the base and the surrounding organs. Pay attention to whether there is pus or blood on the finger cuff after withdrawing the finger. Do not press the tumor roughly or forcefully during digital examination to avoid tumor rupture and bleeding and tumor spread.
2. Endoscopy: Through the endoscope, you can directly observe the anal canal, rectum, colon for congestion, edema, ulcers, new organisms and other lesions, understand the location of the lesion, the size of the lesion, and the nature of the lesion, especially for early detection of lesions. It is of great value for early colorectal cancer and precancerous lesions. Commonly used endoscopes are anorectoscope, sigmoidoscopy and fiber colonoscope. Once a suspicious mass or ulcer is found, a biopsy should be taken for pathological examination. If the pathology is negative and clinically suspect, the examination should be performed twice or more.
3. CT or MRI: CT or MRI examination can determine the size and location of the tumor, the depth of the invasion of the intestinal wall, the relationship between the tumor and the surrounding nearby organs, whether there is peripheral lymph node enlargement, and help to determine the surgical resection of the tumor before surgery Possibility.