I know that wood chips can hold moisture, so if you have a water dish that can get the chips wet and cause them to retain the water. I'd throw out all the bedding, clean the bottom of the tank real good and maybe move him to shredded newspaper or something cheap and easy to clean till the problems pass. Depending on how long this has gone on for simple habitat changes may be too late. I really suggest having your friend take your snake to the vet. How long till you get home? I'd really worry about how far the RI has progressed... So it's really crucial that he gets to a vet ASAP. Here is an article with some good information.
http://www.anapsid.org/rti.html
http://www.anapsid.org/ibd.html is all the more reason to get him to a QUALIFIED herp vet.
http://www.anapsid.org/rti.html
http://www.anapsid.org/ibd.html is all the more reason to get him to a QUALIFIED herp vet.