When food or any other foreign body goes into the lungs instead of the stomach, your child will try to eject it out with a lot of sputtering or coughing. It is nature way of removing alien bodies from the lungs and getting it back to the throat.
As long as the child keeps coughing and is not turning blue or grey in the face, you do not have to worry. He is getting plenty of air and will "cough it up". Some sharp pats on his back between his shoulder blades may speed things up. But he may cough up food or drink so violently that it goes into his nose. It will be painful, especially if the substance is acidic, but not dangerous.
But, choking on objects like a marble or a button could be. It may become wedged at the back of the throat blocking the air passage. If the child is coughing, you need not worry too much. The fact that he is coughing means that some air is getting past the object, or he would not be able to cough. Put his across your forearm or knee so that his head and chest are lower than his legs and hips and pat him between the shoulder blades until the object is coughed out. Start this process fast because if the child goes on choking without the clearing the blockage, the muscles of his larynx may go into a spasm, clenching around the object. This will make it even more difficult for the child to breathe.
If the child is not coughing but is gasping, turning scarlet and then greyish, with an expression of panic in his eyes, he cannot breathe. Act fast. Open his mough and put your finger boldly in to the back of his throat in case you can hook the object. If you can make him retch, even better, this may dislodge the object.
If this does not work, you could try the "Heimlich manouevre." It is risky and you may cause damage. But, you might save his life. Ask your doctor to show you the technique of pushing out the object with your fingers.
Lay him on his side and tilt his head back slightly. Support his back with one hand and place two fingers of your other hand about half way between his navel and the point where the botton of his ribs forms an inverted V-shape. Press inwards and upwards with a quick thrusting movement.
If you are ever faced with a situation in which an adult is choking, the procedure is exactly similar except that you have to use both fists instead of your fingers.
The moment the obstruction shoots out, the child should take a huge breath and begin to recover his colour. But, do take him to a doctor to check all is fine with the child. If the child does not start breathing normally when the blockage is removed, carry out artificial respiration immediately.
Do not leave a baby alone with food or with a bottle. Put him to sleep on his side so that if he brings up some milk, it will run harmlessly out of the mouth and not be inhaled. Do not let your child play with anything small enough to be swallowed, especially if it is round and smooth. A marble will not only be difficult to remove because of its smoothness, it will cut off all air from going in.
Do not give grapes, cherries or stoned fruits like plums to a child who is too young to know that it is to be spit out.
Do not give uncrushed peanuts to babies, toddlers or pre-school children. Eanut can be inhaled without obstructing the air passage but its oils can cause severe damage to the lung.
Do not let toddlers eat while they are running around and do not let older children play games involving throwing sweets or raisins in the air and catching them with their mouths.