Not the writer of this information
Rockitis (a.k.a. Rock In The Mouth)
Symptoms:
Fish will yawn and appear to be imbalanced in the water, with their head significantly lower than their tail (as if they were standing on their head).
Cause:
The fish has ingested a rock or gravel and is unable to spit it back out.
Treatment:
You need to remove the gravel from the fish's mouth or else it will eventually die of starvation. To do this, net the fish and as you bring it to the surface, it will open its mouth. If not, gently open its mouth with a fingernail or tweezers. At this point, grasp the rock with long, round-tipped tweezers and pull it out. If it does not come out easily, you can try turning the rock inside the fish's mouth to loosen it and then pull. To prevent this from reoccuring, you might consider replacing your gravel with gravel that is too large to fit in your fish's mouth.
Note: Only handle fish with wet hands and hold them gently. Never keep them out of water for more than 2 minutes, although this should only take 30 seconds. If you are unable to remove the rock, keep trying. Return the fish to the water and try again after it has rested for a few minute
Sometimes just removing them from the tank in a wet tank water cloth is enough for them to get the stone out.