Hen with persistent diarrhea - vet can't find any obvious cause

[Banana01]

That's interesting about the corn. I was feeding them Kelley's Lay Pellets before I switched to the Purina, and the problems originally started on that feed. I haven't tried adding any other kinds of grains to the diet, so maybe it would be worth trying some corn.

I'm also hoping some of the diarrhea will clear up after she finishes her molt. She started much later than the other hens and is kind of a hot mess right now.

You said it was almost explosive diarreah, which indicates gas is building up in her intestines. Gas comes from fermentation and fermentation is caused by those synthetic fibers i mentioned above, or rather the synthetic fibers are prone to fermenting more than natural fibers, it's a known side effect.

So maybe her digestive system is a bit sour right now. I dont know the best treatment for that. I know I might give some electrolyte with baking soda. But im not recommending anything other than a 10% good fiber source supplement.

 

[Pickychicks]

I really would not keep her indoors now, but let her be with her flock. Otherwise, they may change their pecking order and pick on her if she is missing for awhile. Since you have had all the testing, I don’t know that there is too much more that you can do or monitor. I would just check her vent often to make sure that she doesn’t need a cleanup. Cottage cheese and cooked rice have a tendency to firm up droppings, but I would try some in moderation, and make her layer feed her primary food with no extras. ACV added to water is okay in moderation, but it really is not necessary. Even though your vet saw no worms or parasites, it probably would not hurt to worm her a couple of times a year. Valbazen is good, and SafGuard is as well.

I'm not sure if this will help but generally speaking when there are a lot of things going into a diet and there are digestive problems, my first thing would be to eliminate all supplements in food and water and feed only basic formulated feed for at least two weeks and monitor behavior/droppings.
If this appears to bring improvement, then gradually add back the supplements one at a time at intervals of two weeks to see if there is any reaction with each addition. It's the same method doctors use to find out if people are having allergic reactions to a particular food. Good luck.

 

[RGB RIP]

You said it was almost explosive diarreah, which indicates gas is building up in her intestines. Gas comes from fermentation and fermentation is caused by those synthetic fibers i mentioned above, or rather the synthetic fibers are prone to fermenting more than natural fibers, it's a known side effect.

So maybe her digestive system is a bit sour right now. I dont know the best treatment for that. I know I might give some electrolyte with baking soda. But im not recommending anything other than a 10% good fiber source supplement.

I think you may have had the winning answer. I finally got the Diagel from the vet, but it only worked for a few days. Although I let the girls forage in the yard, I had never bought corn before, because both vets had told me chicken feed was all they need and anything else was just "junk food." But after reading your advice, I bought a bag of chicken scratch with corn, sunflower seed, etc. I've been putting out just a little bit of it in their run every morning. But after a week, she's almost back to normal, with very few runny stools. I think that might have been the problem all along. Hope so, anyway. Thanks for your help!