I'm on tadalafil but do not experience diarrhea. I did have diarrhea when I was sick with a virus.

My doctors have had me take Tadalafil and Uptravi both. Since I have become pregnant my doctor had me stop the Tadalafil. It made me feel when I had to go to the bathroom that I had to go instantly but not a daily thing. Kinda a hit and miss symptom that comes and goes. Hope your symptoms ease.

I could not tolerate taldalafil but have been taking sildenafil for years with no side effects at all.

I get occasional diarrhea, but in time it does taper off. Keep using the Imodium.

I hope its temporary, as I need to take something.
Thanks for your feedback!