Thank you for the query.
which contains blood should be checked with stool tests. Most probable reason of such symptoms is bacterial infection. Especially that you have come back from India recently. The food in India can contain dangerous for tourists bacteria. Some of such diarrhea can be life threatening when not diagnosed and treated. Especially for kids.
That is why it is strongly advisable for your son to have stool tests and stool culture test done and prescribed proper antibiotics. Please visit your doctor and do not wait anymore.
Hope this will help.