Hi doctor. I have had pain in my left side for 2 days. Yesterday I had pain in the left side just below the ribs. Today, the pain has moved down to the left side of the navel. May I ask what kind of illness you have? Doctor please help me. Thank you doctor.

A 31-year-old male with a history of frequent digestive disorders for many years. Recently, I have a dull stomachache with fatigue and loose stools, the pain is on the left side of the navel from 5cm to 1cm low, when pressing 2-3cm, the pain is clearly heard in a certain position. So the doctor told me the dull pain in the abdomen across the navel is a sign of what disease?