Most of the pain on the left side below the navel is due to the following causes: First, the most common is left-sided main colorectal inflammation, the pain is mainly characterized by paroxysmal-like spasmodic pain, sometimes accompanied by obvious diarrhea, nausea, vomiting and other symptoms of the digestive tract. Second, the left ureteral urinary system stones, stones to the bladder in the process of slipping easily stimulate the left ureter caused by left-sided pain, and to the perineum radiation, serious will be accompanied by hematuria and other symptoms. Third, women’s left fallopian tubes, ovaries and uterine adnexal inflammation such as ovarian cysts and other gynecological diseases cause. The pain below the left side of the navel must be seen by a hospital in time to find the real cause and treat the problem.