Why would fecal matter be collecting between the rectum and the anus . Sort of makes an adult feel like they are wearing a diaper that is full. Why would fecal matter be collecting between the rectum and the anus. Sort of makes an adult feel like they are wearing a diaper that is full. No incontinence , no descention, no bleeding, no diarrhea , no burning. It just occasionally collects there and has to be helped out. Age 56, overweight, otherwise healthy. Female. No previous injuries. Have delivered four children. No problems afterwards. Thanks.