I would use the following formula to increase urea excretion:
1 Dandelion root
2 Parsely leaf
1 Burdock
1 Shepherd’s purse
2 Plantain
Combine the herbs as listed and take 2 teapoons of the dry powders in some juice three times daily and drink lots of distilled water.
For the pain I’d use anti-inflammatory herbs and nervines.
This formula is good for inflammation: 
Don't use herbs or combine herbs with medications or use them during lactation or pregnancy without talking with your healthcare provider.