3 year old with frequent urination, always hungry, always really thirsty, stomach aches and random fevers. all related?

Worrisome pattern: I would suggest you take the kid in and repeat this info to the doc in the next 24 hours. It might be minor, but could also be a significant problem.Type 1 diabetes can show up with this pattern.

Here are some ...: A 20-yr lady with a 3-yr Hx of the concerned symptoms as described should be systemically evaluated with detailing Hx on general health, lifestyle, drug use/misuse/abuse if any, overindulgence & obsession, etc. to make sure of no diabetes, no GI disorders with indigestion and malabsorption, rare autoimmune disorders, etc. So, see dedicated PCP ASAP; don't wait, worry, and guess.