Hi Paul. I have had these mucus discharges ever since my ileostomy 5 years ago. The bowel wall secretes mucus which, after surgery, no longer serves any useful purpose. For me, the real problem I had with the leakage was that it showed on the back seat of my pants. Mike's suggestions are great. I take a tissue, roll it up tightly into the shape of a cigarette, fold it in half and then insert it gracefully where the sun doesn't shine. A dab of vasoline helps immensely. The leakage is controlled but I won't leave this "plug" in for more than 4 or 5 hours without changing. Here's a useful brochure on the problem:
http://www.stoma.fr/2530_Rectal_Discharge.pdf
The last thing you want to do is have your rectum sewn up. My GI told me that this operation was complicated and not without nasty side effects. On another note, I wonder why you escaped this problem for 33 years and what you might have done recently to bring it about. Perhaps a change in diet? Anyway, good luck!
PB