Bloating: this can be a side effect of certain food or drinks (such as carbonated beverages) Constipation: can cause a stomachache as well as a bloated, hard stomach Overeating: eating too much at one ...

A hard stomach can happen for various reasons, including constipation, gastric cancer, and some chronic digestive conditions, such as irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD ...