Persistent hidden pain inside the left lower side of the navel may be related to enteritis or intestinal tumors, left ureteral stones, left inguinal hernia, female left adnexitis and other diseases. 1. Enteritis is a relatively common intestinal disease, mostly associated with improper diet and abdominal cold and other factors, in the clinic can be manifested as abdominal pain, can also be accompanied by diarrhea, abdominal distension and other phenomena; the left side of the colon or sigmoid colon tumors may also be manifested as a hidden pain in the left lower abdomen. 2. Left ureteral stone refers to the stone obstruction in the left ureter, causing irritation to the wall of the left ureter and the formation of pain and discomfort, usually accompanied by left renal tenderness, as well as urinary frequency, urgency and other urethral irritation manifestations. 3. left inguinal hernia: due to the sudden increase in abdominal pressure, resulting in intestinal contents forced through the weak parts of the abdominal wall and into the hernia sac, and intestinal contents do not get timely recovery resulting in incarceration, in the clinical will also be manifested as a side of the lower abdomen pain. 4. Women’s left adnexitis: mainly refers to the inflammation of the fallopian tubes and ovaries, the main clinical manifestation of one side of the abdominal pain, as well as accompanied by an increase in vaginal discharge, and may even cause fever, headache and other systemic symptoms. Due to the many causes of the disease, it is necessary to consult a doctor for details.