help-hiatel hernia

I have just be diagnosied with a large hiatel hernia...does anyone know if this will hinder me from have gastric bypass surgery...

Not usually. What happens instead is that they do a repair either when they operate on you, or else they save it for later and when they do the hernia repair you get a free or panni (if you have a generous and experienced gastric bypass surgeon). My surgeon is a general and vascular surgeon as well and he frequently does pannis as a part of hernia repair. Good Luck.