Got gastro ended up at hospital iv n all that, can it turn into a lung infection because they are starting to hurt when i breath in :/?

Not typically: If in fact you have a typical viral gastroenteritis it is unlikely that it will also effect the lungs. Many bacteria/viruses have a predilection for certain body organ/tissue and so it is not likely. It is possible that you are experiencing abd pain due to deep inspiration and the diaphragm is coming in contact with irritated abdominal contents

Pleuritic pain?: Please have your doctor examine your lungs and order an xray if necessary. Pneumonia and atelectasis are known post-op complications. If still hospitalized, ask for an inspirometer to prevent these problems.