How to know if your 7 month old baby has the stomach worms?

The age says NO: A 7 mo old, if he (she) is not crawling, and drinking mainly breast milk or formula, it is very unlikely that he has "stomach worms". If you are living in south, and if you do not have complete sewage system, he may have worms, but you would not know unless his stools are repeatedly looked for worm eggs or worms themselves. He may be simply constipated and thus he has pain when he moves his bowel.