don't medicate with the ingredient i've mentioned unless you're sure your fish have camallanus. it's a very harsh drug and not to be taken lightly. the parasites look very much like strings of worms coming out of the anus. if your observation is that it's shaped like a 'bulb' then it's very likely NOT camallanus. if you have a pair of angels perhaps it's the breeding tube. if not, your fish may have intestinal prolapse. google that and see what you think.
