What's wrong with my ADF?!

[Pekams]

I found my small ADF had a thread in the anus for two days (just as the photo). But its eating is normal, and now I don't find obvious abnormal behavior. I feed it living bloodworms.
Does my ADF get ill in the digestive system? or it just defecates? what should I do now?
Thank you!

[IvyTheBunny]

Have you tried *very* gently touching the thread? Does the frog react with pain, or squeaking? If not, maybe it is a very large piece of poo...a lukewarm water bath may help him to defecate. I don't think any little organs are coming out, usually these are pink.