Looks to me like your little buddy has ingested the sphagnum moss while in transit. It will not digest in his tummy very well and the stress could have caused him to eliminate the stomach problems he developed by eating the moss. Very high in acids, the moss would have upset him for sure. Try feeding a heavy green for a few days, and a luke warm bath on the anus as well would not hurt. the moss itself can still be in the actual digestion track due to the carpeting affect the moss grows in.