Hi I Have A 4mm Calculus In The Right Distal

Hi I have a 4mm calculus in the right distal ureter. Painful for the first few days the. It became stuck in the ureter. Mild to zero pain since. It's been a few weeks-I've changed my ways diet wise per the Drs direction. I had another X-ray Friday and calculus is still in the ureter. They prescribed flowmax and advised a daily serving of lemon.
This morning after eliminating normally a few times(every hour or so) I went a third time right before lunch-still clear/pale yellow but with a white powdery content w small chunks.didnt feel a thing bad but collected as much as I could in a strainer and bagged it. Probably 100mg worth. It's like corn starch.l and hard to secure in water bowl. Ever heard of such a thing?