Is it normal that my three week old son went limp after turning red from crying and one min later went back to normal 4 days ago my wife was holding him and he went limp and he was awake at the time then fell asleep again, he also is having trouble poopin

Any . Any time a child has an episode of apnea (stops breathing), with choking, gagging, change in muscle tone (such as going limp like your child did) and/or color change - especially turning blue - it is known as an alte or apparent life threatening event. When this happens you need to call your child's doctor immediately or go to the emergency room for evaluation. 50% of the time a cause is not found, which means the other 50% of the time the cause is found. The list of what it could be is enormous - it could be a number of problems with the gastrointesinal system, neurological system, a cardiac or respiratory problem, infection, or even a metabolic problem. Doctors will do a complete history and physical followed by testing to try and determine the cause of these episodes.