Egyptian, right? That means he's eating vegetation? It really shouldn't smell all that bad. Little russian tortoise poo smells pretty bad and they eat only vegetation too. Try to get a bit more grass into the tortoise. More fiber and it should come out a bit drier and more firm which equates to less smell.
If so, I would start off simple: Is there a suspicious part of her diet that you are unfamiliar with or concerned about??
The first time I let my tort eat a hard-boiled egg, she had an incredibly strong smelling stool the next day, but I stopped feeding her eggs and it's never happened again since~