My son was given vancomycin (iv) at just over 2 weeks of age. It was to treat a bacteria infection. It turned out that my son did NOT have an infection, the growth from his blood culture was a contaminent! He was given Vancomycin for 2 days! For NO reason! Ever since he has had severe abdominal pain/gas, etc. Could this be related? He has had no blood in stool. But like I said, extrememe abdominal issues/pain.