how can i give myself diarrhea?

(TMI ahead) i know this sounds crazy but i have not passed a bowel movement in a few days. the last time i did i had a really hard time getting it out, and the last bit never came out, i pushed and pushed and it would not come out. since then i have not had the urge to pass a bowel until today, and it will NOT come out. (i think this problem is due to my switching prenatal brands and i think this new brand is constipating me.) i have labored on the toilet multiple times and taken 2 stool softeners today. it is too painful to get it out. i honestly at this point would love to have diarrhea so i can just clean myself out without feeling pain. how can i give myself diarrhea SAFELY? i’m also 23 weeks pregnant.