My son had pyloric stenosis and had surgery on9/12/14 he now is always crying like he is in pain, wont bring up wind and only poo's every 2-3 days, ??

Recurrence risk. Although a small percentage of children treated for pyloric stenosis will develop a recurrence following surgery, the symptoms you have described are not typical of an upper GI obstruction but more of a lower one. Your pediatrician or surgeon should be advised of the new development and would most likely ask you to schedule an in person consultation. Best wishes.
Crying. You could be dealing with either colic or reflux. See if your baby is spitting up. Check if breast fed or formula fed.