Real fit size small???

Hi there,
Wanted to say the new real fit have been a huge leap over the previous pull up style diapers, but why isnt there a small size? I have been dealing with stress incontinence issues since my late 20's now 33 and lead a very active lifestyle. I am a active runner and weightlifter and currently have a 31" waist being 5'8" and weighing 175. The small/medium going from size 28-40" waist sucks since the back drops. Any thoughts of dedicated size small?