Not cooked rice, but rice cereals like Chex do.
I just discovered recently that Oatmeal plays havoc with my hiatal hernia ,
I also found out (through some research), and it works for me , that an apple will
stop any heartburn.
I have the same problem with getting bad heartburn after eating oatmeal.
I went to an allergist because I was having other GI issues that I thought were caused by an allergy, and I had her throw the oatmeal protein into the panel she was doing. It turns out that I am allergic to oatmeal. She did a skin prick test, and it was the only thing that gave me a weal.
The oatmeal protein is very similar to some of the other grain proteins (ahem, gluten) so it is not surprising that eliminating grains fron your diet would make you feel better.
As for the heartburn after eating rice that one poster described, an allergy to rice is not unheard of.
Just one more thing you could ask your doctor about. 
Well, at the time it was because I’d had an entire lifetime of doctors scolding me for not eating enough whole grain foods and the conventional wisdom was that animal foods and fat were Satan. Also doctors always treated me like I was a fatty, fatty, liarpants when I insisted that I was eating a strict low-cal, low-fat, whole grain diet and still having heinous reflux issues and constantly gaining weight and that the solution was to cut out all the sweets and fats I was probably sneaking and eat more oatmeal.
For me a half dozen almonds will do it, stops it cold. If I take tums or other antacid medications it just bounces back within an hour or two. For whatever reason munching a few almonds cuts the cycle immediately.
Add me to the list of rice heartburners. Really any grain foods in any significant amount will do it. Oatmeal is the most drastic, corn seems the least. Rice is somewhere in the middle, which is a real shame since I grew up in rice-growing country and white rice with salt and butter is my ideal comfort food.
After that follow up, I was totally grain-free for two years, got in pretty good shape (lost >100lbs), then got profoundly depressed and eased back in to eating some rice and gluten free products and put some back on with a corresponding return of acid reflux issues and elevated blood pressure–though the reflux is extremely mild and predictable compared to what I lived with for all those years. In avoiding gluten I seem to be able to stop the most violent symptoms (constant diarrhea, aspirating stomach acid in the middle of the night), but any significant grain/sugar intake still causes noticeable discomfort and weight gain.
Hi NajaNivea, I have sent you a private message…
I also get heartburn after I eat oatmeal. It doesn’t matter what consistency it’s in, if it’s cooked on the stove or if it’s instant, and if it has milk or doesn’t. I tend to get acid reflex when I eat fatty and fried food. When I was trying to do some research into why I get heartburn from something that doctors say is healthy, I saw a video explain that acid reflex is sometimes caused by too little acid. Why do I want to eat oatmeal, even though it gives me heartburn? Because it has protein, fiber, very little calories, and it fills you up. I don’t have time to graze. Also, like what @NajaNivea wrote: “…I’d had an entire lifetime of doctors scolding me for not eating enough whole grain foods…”. I have some digestion issues, which I need to finally see a doctor about. Too much milk causes diarrhea. Greasy food and fast food also just sits like a rock in my stomach. Finally, every single night, whatever I eat - causes me to balloon out like I’m pregnant. I did some research and learned that digestive enzymes have helped others with my problem as well as probiotics. I’ve been taking probiotics for several years and it’s helped a little bit. I noticed that when I take the enzymes, that I don’t have the same issues as I was having. If I forget to take them, I balloon up. Today, I cooked some oatmeal from the brand “Bob’s Red Mill”, because I wanted to see if enzyme supplements would help me. This morning, I took both Lactaid for my milk intolerance, since milk was in my oatmeal and the brand “Now” - Super enzymes. It breaks down fats, carbs, and protein (but doesn’t have lactase). Maybe oatmeal’s protein and complex carbs are hard for my stomach to break down, because I don’t have enough stomach acid and maybe I don’t make as much enzymes as I used to (I’m 43 years old). Or - maybe I have an oat allergy like @RusticApples. Those two supplements really helped! I didn’t have one acid burp! Regarding rice: I don’t seem to have a problem. I do cook white rice with quinoa (half rice, half quinoa).