Everyone needs to know about the symptoms of colorectal cancer

Colorectal cancer is a malignant tumor. The occurrence of this disease is related to many factors, especially lifestyle, genetics, colorectal adenoma, etc. Colorectal cancer includes two types: colon cancer and rectal cancer. The age of onset tends to be older, and the incidence rate in men is higher than in women. Everyone needs to understand the symptoms of colorectal cancer so that the disease can be discovered early and treated as soon as possible.

In the early stage of colorectal cancer, there are no symptoms or the symptoms are not obvious, only discomfort, indigestion, occult blood in stool, etc. As the cancer develops, symptoms gradually appear, manifested as changes in bowel habits, abdominal pain, blood in stool, abdominal mass, intestinal obstruction, etc., with or without systemic symptoms such as anemia, fever and weight loss. Tumor metastasis and infiltration can cause changes in the affected organs. Colorectal cancer shows different clinical symptoms and signs due to different locations of occurrence.

1. Right colon cancer: The main clinical symptoms of right colon cancer are loss of appetite, nausea, vomiting, anemia, fatigue, and abdominal pain. Right colon cancer causes iron deficiency anemia, which manifests as fatigue, weakness, shortness of breath, and other symptoms. Because the right colon has a wide intestinal cavity, abdominal symptoms will not appear until the tumor grows to a certain size. This is also one of the main reasons why the tumor is diagnosed at a late stage.

2. Left colon cancer: The left colon cavity is narrower than the right colon cavity. Left colon cancer is more likely to cause complete or partial intestinal obstruction. Intestinal obstruction leads to changes in bowel habits, constipation, blood in the stool, diarrhea, abdominal pain, abdominal cramps, bloating, etc. Stool with fresh blood indicates that the tumor is located at the end of the left colon or rectum. The disease is often diagnosed earlier than right colon cancer.

3. Rectal cancer: The main clinical symptoms of rectal cancer are blood in the stool, changes in bowel habits and obstruction. Patients with lower tumors and harder feces are easily rubbed by feces and bleed. The bleeding is mostly bright red or dark red, not mixed with formed feces or attached to the surface of the feces column, and is misdiagnosed as "hemorrhoidal" bleeding. Secondary infection of lesion stimulation and tumor ulcers constantly causes defecation reflexes, which are easily misdiagnosed as "enteritis" or "bacillary dysentery". Those with ring-shaped tumor growth will lead to narrowing of the intestinal cavity, which is manifested as deformation and thinning of the fecal column in the early stage and incomplete obstruction in the late stage.

The most common form of infiltration of colorectal cancer is local invasion, where the tumor invades surrounding tissues or organs, causing corresponding clinical symptoms. Anal incontinence and persistent pain in the lower abdomen and lumbosacral region are caused by rectal cancer invading the sacral plexus. Tumor cells implant and metastasize to the abdominal and pelvic cavity, forming corresponding symptoms and signs. Rectal examination can palpate masses in the bladder-rectal fossa or uterine-rectal fossa. The tumor is widely implanted and metastasized in the abdominal and pelvic cavity, forming ascites. Therefore, early treatment is critical for this disease.