Gently run some warm water over their little bums and loosen the poo that is stuck on there. Then, when they are clean, apply some vaseline or neosporin, without pain med, to the vent area to help keep the poo from sticking again. Put some ACV into their drinking water for a couple days. This is called pasty butt and there are many links on here to help. I think it is 1 tsp ACV per quart...this should take care of the problem. Make sure that you watch for this to recurr at least twice a day. Immediately clean off any poo and reapply the vaseline, etc.