I have been told i have a 5 cm hiatal hernia have had a fundoplication 9 years ago dr thinks stitches may have come loose is this possible?

yes its possible: If your hiatal opening is that large now, it would not matter if the wrap slipped. Its large enough to let the stomach slide up into the chest. Consider discussing this with a surgeon. A robotic or laparoscopic surgeon likely is your best bet.

Yes: Recurrence of hiatal hernia and disruption of fundoplication can definitely occur. Not sure if you have had upper endoscopy or radiologic studies (e.g. Barium upper GI series or cat scan) to confirm this. Based on severity of symptoms, redo surgery may be needed and can typically be accomplished laparoscopically or robotically.