"Tummy problems" refers to any discomfort or issues in the stomach area. It can include things like stomachaches, nausea, vomiting, or diarrhea that can make you feel sick or uncomfortable. Full definition
The second time around, I had a very fussy baby with tummy problems and a very demanding toddler that wouldn't let me sit still long enough to nurse. (babybunching.com)
Your cat does not need milk, in fact some cats are lactose intolerant and cow milk will cause tummy problems. (best-cat-art.com)
When I stay gluten - free, I have more energy and fewer tummy problems. (acalculatedwhisk.com)