Increased side effects of stimulants after bowel movements?

I (24F) am on 54mg Concerta, and I have noticed that after a bowel movement (usually happens within 2 hours of taking the meds), I immediately get pretty bad tremors and shakes in my whole body. I get these internal vibrations too and although it isn’t debilitating, it is quite uncomfortable. My hands definitely shake a lot which is kinda problematic, and then the nausea comes an hour or two later. Food usually curbs the nausea, that is if I am able to actually eat. Does anyone else experience this? Do you have any advice for how I can reduce these post-number 2 tremors? I used to have this issue when I took caffeine before. but I feel like with the meds, it’s a bit worse.