Voltaren Gel is a very good medication and many people get excellent results from it, but the gel has all the same side effects and concerns as the oral version of Voltaren.
The gel form can still stir up gastric problems, and can still make an old gastric erosion bleed. I remember the doctors at the last hospital I worked in being very particular about us nurses not using it on patients with a past history of ulcers....not ever.

MrsD would be able to give you more information should you wish to address your concerns to her in the Medication Forum.