Ok, hopefully, the hen will be able to get enough poop out, but the more solid ones would have trouble coming out of small openings. From what you wrote, sounded like she completely closed up the vent. Did she stitch in the center or the side of the vent or did she completely close up the vent? I still think that if she was egg bound and the egg was extracted, and not even prolapsed, stitching up the vent was a very bad idea. If feces back up into the oviduct because they cannot come out normally, your hen will develop an ecoli infection and you have a whole other issue to deal with.