Persistent dull pain in the upper right abdomen lasting two months is very likely a clinical symptom caused by colon cancer. This is often due to the lesion of colon cancer invading the intestinal mucosa, causing mucosal spasms and resulting in pain. Alternatively, the tumor may cause obstruction of the intestinal lumen, leading to intestinal obstruction, which also presents as pain clinically. This type of pain is generally characterized by persistent dull pain, especially more pronounced at night, and ordinary anti-inflammatory and analgesic drugs are less effective in relieving it. The pain will only subside after the lesions of colon cancer are effectively controlled. However, for dull pain in the upper right abdomen, some benign diseases, such as certain ulcerative colitis or chronic intestinal tuberculosis, should also be considered, as they can present with similar symptoms. To definitively diagnose whether the dull pain is caused by colon cancer or a benign colon condition, it is generally necessary to complete related imaging or hematological examinations. Sometimes, histopathological examinations are necessary to differentiate the diagnosis.