The vast majority of child/youth bed wetters sleep too soundly to know when to wake in time to void in a toilet rather than their bed. Does medication help the physical control of bed-wetting issue? No
Here's a recent article that says the hormone desmopressin (DDAVP), commonly used to fool the body into not making urine is no better than behavior modification, alone. In brief, the researchers compared the efficiency of desmopressin to simple behavioral modification techniques in the initial treatment of "monosymptomatic" nocturnal enuresis (PMNE) or bed wetting.
Note: DDAVP can be dangerous; when you need to make urine for instance, when you have drunk too much water, you can't. That's what this hormone does—it prevents a physiological or normal process.
The sample was demographically homogeneous with respect to gender males/females (etc.) The use of desmopressin resulted in a statistically significant reduction in the average of PMNE episodes but so did behavioral modification with no statistically significant difference between desmopressin and behavioral modifications.
Fera P, Maria Alice dos Santos Lelis A, Regiane de Quadros Glashan R, Gonzales Pereira S, Bruschini H. "Desmopressin versus Behavioral Modifications as Initial Treatment of Primary Nocturnal Enuresis." From Urologic Nursing as posted in Medscape.com