What Causes My Infant To Vomit Multiple Times, Including Milk, Food, And Water, After Meals?

Hi, my 7.5 months old has vomited after having dinner , almost an hr later. She ate some chapati bits and then had feed. At first she vomited all the milk n some food she was having , then she kept on vomiting after every 5 minutes. Later everytime she was just vomiting all water and some froth. She vomited almost 6 times. Also she had to put lot of pressure in vomiting but hardly some water was coming out. What s this . This has happened for 2nd time this week