What is required when there is stickiness after drying oneself with towels or with water?

If the stickiness after istijmar (cleaning with stones/tissue) or istinjal (cleaning with water) is not merely a doubt or a whisper (of Shaytan), then it must be removed, because it is residual discharge and indicates that the istinjal was not properly performed. The criterion for thorough cleansing with water is the return of the area's roughness to its original state. However, if the discharge has spread and gone beyond its usual place, then only water is sufficient for cleansing, because istijmar is a concession only for the usual place of discharge.