Diagnosing health issues by looking at fish poo

[Manky Sanke]

Duncan,

While Googling for some information on koi eggs and fry I came across a Koi health website article that said that fish health can be diagnosed by examination of their poo and which included this statement.
Zig Zag or clear poop - The fish is reabsorbing its eggs.

I know that some disorders show in the type of poo but zig zag indicating reabsorbing egg?? Is there any truth in this statement in particular and, for that matter, in the other diagnoses in the list?

Poop diagnosis technique for fish

You can tell alot about a fishes health from their poop. Dont titter! A good poop is generally short, chunky and reflects the colour of the food they have recently eaten. However if the poop changes it can help with the diagnosis of problems.

Long thin poop - Not eating well, possibly stressed or ailing.

Thick long poop - Constipated or over feeding. If it looks like its coming out exactly as it went it the fish will not be digesting it properly.

Zig Zag or clear poop - The fish is reabsorbing its eggs.

Very thin stringy white poop - usually a sign of an internal bacterial infection. Double check for other signs tho if a white or pale food is being fed to the fish.

Clear Poop with bubbles - Fish is not eating well or is eating bubbles, sometimes a sign of gill irritation.

Dark sausage like poop with long mucous like casing often floats - Foods are being fermented by gas trapped within, causing bacteria. Fish may also be eating bubbles, or eating floating food.

No poop, but water is tinged brown - Fish may have diarrhoea or be passing blood. A sign of serious problems.
Extract from: http://eekers.paper-tigers.org/fishnthings/disease.html