If your brother really has internal bleeding, it probably means he was looked at by a doctor and is under treatment for it, such as getting rest at home if it is not too serious. If he was not looked at by a doctor already, you must immediately take him to be seen, or just go to the emergency room, since it can be very dangerous.
Make sure to follow all the advice given by your brother's doctor, such as seeing if he has certain symptoms that may require him to get more treatment or even surgery. I'm sure your brother will be fine, but needs to be under the proper care.
