Is gerd, which does not respond well to medications , and other intestinal problems usually indicative of scleroderma?

No, too big a leap!: "refractory" gerd may reflect: 1) too little acid suppression (insufficient acid blocker or tolerance to previously effective dose), 2) over-production of acid, 3) significant diet & behavior non-compliance, 4) incompetent lower esophageal sphincter &/or other esophageal dysmotilities, 5) delayed stomach emptying, 6) biliary/pancreatic disease, 7) non-acid reflux. Scleroderma is way down the list.

Not scleroderma: Scleroderma is a rare condition and almost always has obvious skin involvement if there is GI involvement. Your gastroenterologist can tell you that there are many reasons that GERD may not respond to antacids. You may require additional testing but many causes of GERD are treatable.