Hey Martha,
I too suffer with the same side effects especially by the third day. When you last took Mestinon did you try taking Immodium for the diarrhea? That really helps me. Also, did you always take it with food...not just a cracker, but after a meal? This also helps me. I hope you are able to tolorate it better now so you can start feeling better. I know too well what it's like when other meds don't work or you can't take them. Take care.
Hugs,
Pat