Low back pain in colon cancer patients is usually seen in tumors of ascending colon or descending colon, because ascending colon and descending colon are on both sides of waist of human body, which belong to interperitoneal organs, and colon tumors may press the nerves of lumbar region to cause patients to have low back pain if the growth is relatively large. It is also possible that the tumor is bigger leading to the invasion of ureter, thus causing ureteral obstruction, then there may be the symptom of lower back pain, and there may be a decrease in urination or there may be blood in urine. There is also a possibility that the colon tumor is relatively late, and there are lymph node metastasis from the root of the mesentery or retroperitoneal lymph node metastasis, and the metastatic lymph nodes are fused to form a mass, which may also cause low back pain, which is mainly caused by the invasion of retroperitoneal nerves.