blood in stool from taking whey protein

I got diarrhea ever since I started taking whey protein. I found out that because I am lactose intolerant, that would be a side effect.

I decided to take Lactaid along with the whey protein to help break down the lactose. Ever since I took those two together, going to the bathroom has been a little painful. There is also bright red blood in my stool.

I have stopped taking any supplements hoping that the symptoms would go away. There is still blood and pain but I want to think that the problem is subsiding.

Has anyone experienced this before?

Thanks