Thanks for contacting healthcare magic.
You have problem of stomach bloting.
Ultrasonography show negative result.
Irritable bowel syndrom may rule out because it can diagnose by
colonoscopy only.
Avoid sressful condition.
Avoid gaseous foods like cabbage, cauliflower etc...
Drink more water.
Do excercise more than 30 minutes.
Avoid spicy and oily foods.
Indigestion may cause bloting in stomach.
malabsoption syndrom may rule out.
Infection of intestine by bacteria may cause bloting like symptoms.
Gasroesophageal reflux disease may cause abdominal bloting with acidity.
Lactose intolerance may rule out.Milk items not digest properly so it cause bloting in stomach.
Colonoscopy can done for further diagnosis .
Wish you a good health.
Take care.
Thanks.