Dr. Shen described irritable pouch syndrome (IPS) as early as 2002, and has done most of the studies to help define and treat it. More recently, he has discovered serotonin secreting cells are increased in pouches with IPS, which might explain why antidepressants often are useful.
It is true that with IPS, you can have a perfectly normal pouch, without pouchitis, cuffitis, or bacterial overgrowth, but still have pouchitis symptoms due to IPS. Just like IBS, it is a functional problem where there is a heightened awareness of gut sensations. Basically, those without IBS or IPS have the same pressures, rumblings, cramping, etc., but just are not sensitive to the sensations.
IPS sounds like a terrible problem. I know they are doing a lot of research on probiotics for treatment of IBS. I'd think they'd probably be useful for IPS too. My husband has IBS along with UC and has seen improvement since he started Align probiotic.