HumanFly:
Are you talking about the style like a Tena Stretch pictured below? I agree with you that the fit in the rear is a bit strange in that it isn't 100% full coverage but at least in my case it is adequate and I haven't had any leakage issues. I agree with JD that you may need to get the next size up to get the coverage you are looking for.
BTW...I like to wear this style diaper in the hot and humid summers here in Florida, I find them much cooler than others with the fully enclosed sides. In the cooler months I often wear Abena L4's and ComfiDry 24/7 and haven't noticed a difference in the cut or shape.
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Tena Stretch Daiper.jpg [ 18.3 KiB | Viewed 4943 times ]