Question: what does it mean when you feel pain on the left side of your stomach?
Answer: In many cases, persistent pain specific to the lower left side of the abdomen is caused by diverticulitis. Diverticula are small pouches created from pressure on weak spots in the colon. Diverticula are common, and even more so after age 40. When a pouch tears, swelling and infection can cause diverticulitis.