You are having diarrhea
(enterocolitis). You should avoid any meals which contain a lot of cereals or that have a lot of sugar for now. Take oral rehydration solution ( mixture of 1 sachet oral rehydration salt and 1 litre of clean water) and drink 2 to 3 litres daily. Antibiotics will not be necessary. But you could include metronidazole
so to take care of any enteric germs that might also cause loose frequent stools.
If this persist, please consult your doctor for further evaluation.