Bad cramping before pooing?!

[88london]

Hi all,
I'm 6+5. I'm getting really bad cramps that seem to ease off when I use the toilet. I also have diarrhoea.

Did anyone else experience this or hear about it?

I don't have any spotting and definitely no constipation!!

I'm 30 weeks and have had this throughout the pregnancy. It worried me a bit at first as this is my second and i didn't have it in my first pregnancy but I'm just used to it now.