IBS vs Endo, how did you know?

Hey all! I've noticed IBS gets floated around a lot in convos about endometriosis, usually as a result of misdiagnosis or because the two are often comorbities.

My question, depending on your situation, how did you know that you either:

1.) Had IBS but not endo? 2.) Had endo but not IBS? 3.) Had both?

Again I know there's overlap here. Anything you can share is much appreciated and I thank you in advance!