My stomach feels fullness, hard and gain fat. what is the cause and which treatment you recommend ?

Bloating due to gas.: Or gas x. Try to identify and avoid the foods that affect you the most. Foods that cause gas problems for many people include beans, onions, broccoli, brussels sprouts, cauliflower, artichokes, asparagus, pears, apples, peaches, prunes, sugar-free candies and chewing gum, whole-wheat bread, bran cereals or muffins, milk, cream, ice cream, ice milk, and beer, sodas and other carbonated beverages.