Thanks for explanation - I am better educated in medical terminology now but Wikipedia sure needs someone to write an article to explain clearly as did your link.
Btw I have been through some of what both you guys relate and my most painful experience was urine retention after an operational epidural. Never in my life have I been so pleased to see a nurse with a catheter and I am told that the pain of renal colic is worse than childbirth (I won't argue with that but never suffered the latter to compare !)