Baby poo

My daughter is six weeks old she was acting fussy and kept wanting to nurse. Finally she had a bowel movement and it was yellow and mustardy but also parts of it were like water and shot out of the diaper. It also didn’t smell as if normally does (that sweet smell). It was a very strong foul smell. Whatcould it be? Something I’ve eaten? I’ve never smelled her poop that bad before.