First of all, what kind of cichlid(s) do you have and what do you feed them.
Long, pale feces, not eating and hiding away is very likely to be "Malawi Bloat". You don't have to doubt if abdominal swelling is visible.
I have used a medicine called "Octozin" with success when my Yellow Lab was infected some time ago. But I do recommend asking your LFS as there are more medications (brands) to cure bloat and I’m not sure whether they sell Octozin.
Best you can do is to isolate your cichlid, that is, if you've got a spare tank.
It is not really contagious, the "infection" is mostly due to too much protein in their diet. Some other fish could be affected as well. So be on the lookout for that.
Good luck and I hope he will recover.
Edit: I assum the water conditions are OK, less than .2 ammonia and less than .2 nitrite?
Jimmy.