I've just come out of hospital and had a very frustrating time with mucous/water constantly leaking from my back passage - especially overnight. I've been told its just how it is...and that I kind of just have to put up with it until it settles down. Not sure if this is exactly the same as your situation but from my little experience I've just been told its leftover from the surgery and will settle down over time.
24 y/o female from UK dx with UC (Proctitis) Jan 08. Never fully been in remission, resistant to all meds apart from Pred and Infliximab. Also dx with IBS. Proctocolectomy+pouch surgery w/ temp loop ileostomy 9th April 11.
Currently taking daily:
Spasmonal x 3, Cyclizine x 3, Tramadol x 6, MSR (slow-release Morphine) x 4, 60mg Seroxat (anti-anxiety), Multivitamins