I had a pain on left side upper abdomen after I drink a water and eat abit. The pain continue to left side of my back and chest (very painful).diseases?

Splenic flexure synd. most common cause of this at 28 yrs is a gas pocket stuck in the upper left part of colon, causing distention and pain in left upper quadrant of your abdomen, that can also felt in back or lower chest on that side; this is known as splenic flexure syndrome; take some OTC gas pills and it will pass. Any assoc sx, such as fever, vomiting, diarrhea, or persistent pain more than a few days, see doc.