The GI issues are caused by the creatine absorbing water. This causes your gut to have more water than usual as it follows the creatine through the works… which causes… urgency.
The effect diminishes after you’ve been taking a regular dose for a while, even with just monogydrate (not HCL).
Some people say HCL causes less distress because it doesn’t draw water as much. Others argue that defeats the purpose of taking it.
Monohydrate is studied to death and proven effective, HCL not so much.
But otherwise, I'd agree that monohydrate has significantly more research behind it and I'd default to that if it's tolerable.
Have a friend with sensitive gut. He has to use protein extract instead of concentrate due to issues from lactose.
He had issues with creatine too and switched to Creapure, which is monohydrate from one factory in Germany producing just that. With their nazi like attention to details and certification. It's sold by multiple providers.
The aforementioned friend has no issues now.
Instead of switching from cheapest to most expensive, I take a mid-shelf creatine that also has some certs and never had issues. hn hates name drops, but it's a Polish medium price supplement company. And I use pills, because I just hate the hassle of measuring and mixing it. Eat 10g in 8 big pills.
It's even more anegdotical, but supposedly some cheaper brands give you bad stomach because to save money they use the same production/packaging line without expensive thorough cleaning in between products.
But the logic about water absorption makes more sense. And it would be rare to have such high level of people with issues from creatine just because of negligent cost cutting production/packaging practices. OTOH, I work in food production myself and heard some people say how things look in other places and could believe that people get bad stomach at least from some producers/packagers/resellers.