I have livedo reticularis, bulging veins, non-healing body acne, off/on fever, gi bleeds, diarrhea alt w/constip, migraines, shocks of pain neck lymph nodes. no ibd, ana negative. any common cause?

complicated question: Pika this is not one for the internet these can be caused by a variety if illnesses. Autoimmune problems come to mind. First you need a good internist, consultation with rheumatologist as well. These persons must be board certified in their fields as well. I would be surprised if your illnesses were not related to a central cause of either an immune nature, or lymptatic system disturbances.

No common: Problems can explain your constellation of symptoms. This is a tough one. An infectious disease or rheumatology specialist might be able to help you.