Stepping on a cat’s stomach could cause damage to organs like the liver, kidneys, spleen, bladder, or intestines. It could also cause a rupture of the diaphragm or abdominal muscles and internal bleeding.
If you’ve trodden on your cat’s stomach and they’re acting unwell in any way, you should take them to the veterinarian immediately.
Your cat may need surgical exploration to assess for and fix any internal damage. Of course, surgeries like this can be expensive, and when unexpected traumas occur it highlights the importance of pet insurance.