hi! constipation may be due to several reasons. if she's had it since age of a week then you should get a detailed workup. I would like to know the frequency and consistency if the stools,whether she's able to pass stool without enema.a condition called hirschprung disease may present in a similar way where the child remains chronically constipated and requires repeated rectal stimulation.talk to your practitioner about it. as regards the smell it is due to bacterial overgrowth in stagnated bowel. try some probiotics to promote healthy bacteria in gut and remove the harmful ones. hope I could help.