SAMe is enteric coated and does not even dissolve in the stomach.

The most common stomach thing may be a little nausea, but even then it is not really a common side effect.
Really I know many people who use or used SAMe and the most often complained about issue is the hyper initial effects, which wear off in a few days. Depending on your neurotransmitter status, the hyper thing may or may not happen.

I have a hiatal hernia and a birth defect (twisted stomach and esophagus) and have borderline gall bladder issues, and never had a GI problem with SAMe.

For 10 YEARS!

Everyone is different however. Omega-3's cured my GERD in 3 months. I used to take Prilosec when it first came out. I don't need it anymore!
There are many causes of GERD.

I don't see SAMe causing ulcers... it doesn't even dissolve there.
That person could have had an ulcer already forming, who knows? Internet reports should be taken guardedly.

However, Stacy, if you are the highly anxious type, reactive, etc, SAMe would probably make you more anxious.