Hi Welcome I have gone through your query. It is difficult comment without examination, so kindly get the bruises examined by the local doctor or upload the pictures here. It might be gastroenteritis, but the bruises that you have mentioned may or may not be related to it. I would suggest you to drink plenty of water or electrolyte solutions to prevent dehydration. Add bland foods to your diet, such as bananas, toast, oatmeal and rice in small amounts every couple of hours. Avoid spicy food. Restrict meat for few days. You can take curd which will be beneficial. Take acid reducing agents as suggested by your doctor. Probiotics like sporolac or ecobion will be beneficial. Add curd to your diet. see local doctor Take care