Upset tummy

Hey, so my 1 1/2 year old has an upset tummy like she hasn’t eaten cause it’s hurting her I’ve given her gas drops already and has done nothing too her. This may be irrelevant but coming from a Hispanic family my mom and in laws are recommending me to give her a little bit of alka-seltzer with peppermint tea. I’m just curious as too if I should and if anyone has given there little one some? Or is there anything else I can do or give her? Btw her stomach is hard as well.