Good evening everyone Can you please tell me what this could be? Has a…

Good evening everyone Can you please tell me what this could be? Has anyone encountered something like this? The son has been covered in rashes on his belly, there's no rash on other parts of the body We're currently undergoing massage therapy At first I thought it was from the oil that caused the rash But the next day we did a cream massage and he still turned red on his belly and again had the rash Also, our child started having diarrhea every day for 5 times, changing diapers every time I'm attaching photos in the comments, at first it was a full diaper, now he goes out every few minutes but also 5 times a day His teeth itch but I don't