Can lactose intolerance cause frequent localized pain in upper left abdomen. i get irritable bowel from milk but also have constant left rib pain?

Rib pain: Doesn't appear that this left rib pain would be related to your lactose intolerance which would cause more general symptoms of bloating and loose stools.

Costalchondritis: Constant left "rib pain" likely unrelated to the GI tract, lactose or other. More likely chest wall pain (look up "costochondritis"), or entrapped nerve pain (in this case, left t8, look up acnes - abdominal cutaneous nerve entrapment syndrome).