My diarrhea is similar to yours, except mine is pure yellow. Most times it has a muecus like feature, but it has no kind of oder. I dont know what I have, but if you have a answer, I would very much appreciate it.
The antibiotic you used killed the normal bacterial flora in your colon which has a role in breaking down some nitrogenous nutrients (like protein) and absorption of water. They also form colonic gas which is easier to get rid off.
What the antibiotic didn't do is it didn't get rid of the offending bug which seems to have remained as a chronic gastroenteritis. It's causing the excessive gas in your small intestines which takes longer to clear out, and causing the excessive mucus secretions.
Unfortunately, chronic diarrhea requires going back to the doctor to determine the exact bug (by stool analysis, culture & sensitivity) and targeting it with the right medication.
U can try one thing however, use a probiotic agent (availabe at GNC or elsewhere, and contains healthy bacteria to help improve digestion) for a week and see how that goes.
It sounds like you have classic symptoms of IBS..It wouldn't hurt you to go to your Doctor for a check up,just to be on the safe side.