About one month back ,I had a about of diarrhea,and had to be hospatilised. After that I am facing problem of passing stool(semi formed) after consumption of food and formation of gas.Please suggest the food that can help improve the condition

Are you trying to get a diagnosis from a dr?
Notice what you eat. Many people with colitis or chrons disease colitis diet - Bing (http://www.bing.com/search?q=colitis+diet&src=IE-SearchBox&FORM=IE8SRC) can not eat dairy and many other foods.
You should find out what is causing it and go from there.