(1) Early symptoms: Abdominal distension, discomfort and indigestion may appear at the earliest stage, and then there will be changes in defecation habits, such as increased defecation times, diarrhea or constipation, abdominal pain before defecation, etc. There will be mucus stool or mucus purulent bloody stool in the future.

(2) Poisoning symptoms: Due to tumor ulceration, blood loss and toxin absorption, patients often have anemia, low fever, fatigue, emaciation and edema, especially anemia and emaciation.

(3) Intestinal obstruction: It is a symptom of incomplete or complete low intestinal obstruction, such as abdominal distension, abdominal pain (abdominal distension or colic), constipation or constipation. Physical examination showed abdominal bulge, intestinal type, local tenderness, and strong bowel sounds could be heard.

(4) Abdominal mass: it is a tumor or mass that infiltrates and adheres to the greater omentum and surrounding tissues. Hard, irregular shape, part can move with the intestine to a certain extent. There are many infiltrations in advanced tumors, and the masses can be fixed.

(5) Late manifestations: there are signs of liver metastasis such as jaundice, ascites and edema, and there are also manifestations of distant spread and metastasis of tumors such as cachexia, anterior rectal recess and supraclavicular lymph node enlargement.

Due to the differences in physiology, anatomy and pathology, the clinical characteristics of left and right colon cancer are also different.

The right colon cancer has a wide intestinal cavity, sparse feces, rich blood supply and lymph in the colon, and strong absorption ability. Most cancers are soft cancers, which are prone to ulceration and necrosis, leading to bleeding and infection, so the clinical manifestations are mainly toxic symptoms. However, intestinal obstruction will also occur when the condition gets worse.

The intestinal cavity of left colon cancer is relatively small, the feces have been viscous, and most of them are invasive cancers, and the intestinal cavity is often annular narrow, so the symptoms of intestinal obstruction appear earlier in clinic, and some even appear acute obstruction. Poisoning symptoms are mild and appear later.