Pain on the left side of the navel may be caused by colon lesions, functional disorders, urological lesions, and gynecological diseases. 1. Colon lesions: If there is a lesion in the colon, it will also lead to pain in the left part of the navel, the more common colon lesions are inflammatory lesions, such as ulcerative colitis and tumor lesions. 2. Functional disorders: such as irritable bowel syndrome, can cause functional disorders, resulting in pain symptoms on the left side of the navel. 3. Urological lesions: if there are tumors and stones in the left ureter, it will also cause pain on the left side of the navel. 4. Gynecological diseases: such as left tubo-ovarianitis, ovarian tumors, etc., can cause symptoms of pain on the left side of the navel. It is recommended that the patient is necessary to go to the regular hospital to receive systematic examination, according to the results of the treatment.