Specific manifestations of colon cancer

The entire colon is divided into two parts, the right colon and the left colon, by the middle part of the transverse colon. Due to the differences in physiology, anatomy and pathology between the two, their clinical characteristics are also different.

The right colon cavity is enlarged, and the stool in the intestine is liquid. The tumors in this section of the intestine are mostly ulcerous or cauliflower-shaped cancers that protrude into the intestinal cavity. There is rarely annular stenosis, so obstruction does not often occur. However, these tumors often rupture and bleed, and secondary infections are accompanied by toxin absorption. Therefore, clinically, there may be abdominal pain, stool changes, abdominal mass, anemia, weight loss or cachexia.

(1) Abdominal pain and discomfort 75% of patients experience abdominal discomfort or dull pain, which is intermittent at first and then becomes continuous, often located in the right lower abdomen, which is very similar to an attack of chronic appendicitis. If the tumor is located in the hepatic flexure and the stool is relatively dry, colic may also occur, which should be distinguished from chronic cholecystitis. About 50% of patients experience loss of appetite, fullness, belching, nausea and vomiting.

(2) Stool changes: Early stool is thin, contains pus and blood, and the frequency of bowel movements increases, which is related to the formation of tumor ulcers. When the tumor volume increases, it affects the passage of stool, and diarrhea and constipation may occur alternately. The amount of bleeding is small, and it is fully mixed with stool as the colon moves, which is not easy to see with the naked eye, but the occult blood test is often positive.

(3) Abdominal mass: More than half of patients will find abdominal mass when they seek medical attention. This mass may be the tumor itself or a mass formed by intestinal infiltration and adhesion. The former has a more regular shape and clear outline; the latter has an irregular shape. The mass is generally hard in texture, and once secondary infection occurs, it is limited in movement and tender.

(4) Anemia and cachexia About 30% of patients develop anemia due to continuous bleeding from tumor rupture, and also experience weight loss, limb weakness, and even systemic cachexia.