Hello, Thanks for posting your query. Sever stomach pain can be due to variety of disease like gastroenteritis, gastric ulcer, Irritable bowel syndromes. As you have no other symptoms like vomiting, change in bowel habits or fever etc then gastric ulcer is more likely and should be investigated properly. In gastric ulcers usually pain aggregates after taking meals and relieved by taking milk and antacids. Cyclopam can relieve pain due to stomach spasm. Beside blood and urine test you may need H.pylori test and endoscopy to see detailed picture and bacteria which frequently causes stomach problems. Hope it helps. Take Care!