Gastric problem. To be worried about?

Hello I am a 22year old male from India. Since last few days I have been feeling not good in my stomach. It seems heavy and i would feel need to defaecate. Even after defaecation the stomach dont feel any lighter and i have to make a couple of more visits to washroom. I have observed my stool and it appears to be normal. I dont occassionally measure my weight and it normally measures around 59-60kgs but today i measured and it weighed 57kgs. Now i am worried as to what is the matter with me? I am not correlating my gastric problem to my reduction in weight but cant help not to think about the worst diseases from which i could suffer such cancers or ulcers... Please help me and guide me as to what could be the problem and is there anything to be worried about? Kindly note that I do feel hunger and also able to eat the usual intake of food as before and also besides the above mentioned problems I am not having any other trouble. Please help me. Thank you