Constipation problem. It? please help?

I am 16 year old male I think I am constipated or something like it?I feel that my abdomen is not completely free out of waste after passing stools.I too feel a lot of gas in abdomen and acidity(acid rushes upwards neck).Through my regular stool pattern is one times per two day but now I am going to excrete everyday but with very less stools coming out.Stools too are not very hard they had a high percentage of water in them.In other words,they are like mild diarrhoea.But even after this I feels fulness.I don't know is it due to presence of lot gas in the abdomen or due to less than normal stool amount.I too feel a lot of gas prese Sen in my admonen.These all problem are occurring from a week.I week later I had even vomited once and also found too much gas in my admonen.Is I am suffering from my serious disease.Please help???