Sounds like more than just a worm problem...sounds like it may be an illness running through the flock. The one with the worst immunity to it may be the one that is worst off, or it may be that she was weaker to start out.
I don't know that I would worm them until I was sure it was not an illness...
What did the diarrhea look like? (Did you look at the chicken poop chart?)
Are they underweight? How is the coloring of their ears combs wattles? Are they eating less or more than they used to? Worms will make them eat more because they don't get nutrients...
Have you examined the poop for worms? Have you examined them for external parasites?
These are some "home remedy" type things that have science behind them:
Chickens
Enteritis
http://journals.cambridge.org/actio...e=online&aid=8976474&fileId=S0007114512006083
Capsicum and turmeric
Coccidiosis
http://www.researchgate.net/publica...Immunity_against_Eimeria_acervulina_Infection
Capsicum, turmeric, and shiitake mushroom
Better growth and feed use efficiency
https://dl.sciencesocieties.org/publications/jas/articles/92/4/1531
carvacrol (from oregano), cinnamaldehyde (from cinnamon), and capsicum
And
http://www.researchgate.net/profile...PICE_HERBS/links/549fcd860cf257a635fe78b5.pdf
Garlic, black pepper, red pepper
Newcastle Disease
http://www.sciencedirect.com/science/article/pii/S0378874101003701
Aloe
And
http://ps.oxfordjournals.org/content/85/12/2169.full
Bee propolis and horny goat weed
Salmonella
http://www.uokufa.edu.iq/journals/index.php/kjvs/article/view/2385
Capsicum
Fowl typhoid
http://www.sciencedirect.com/science/article/pii/S037887410100397X
Aloe
Egg shell thickness and reduced bacteria in poop
http://www.tandfonline.com/doi/abs/10.1080/00071668.2014.938020?journalCode=cbps20&
Longevity Spinach
Some varieties of Influenza (this study did not include poultry, but I would try it)
http://www.researchgate.net/profile...za_viruses/links/0f317538efdb7b23d6000000.pdf
Agrimonia pilosa (hairy agrimony of the rosacea family)
This one includes other plants for influenza, but it only shows the abstract.
http://link.springer.com/article/10.1007/s11101-014-9357-1
Mondia: white's ginger a tropical vine native to Africa
Phytochemicals and nutritional status
Studies were undertaken to establish important phytochemicals and its nutritional status to support the traditional claims and enhance the species value for improved marketing and conservation. The main flavouring principle preferred by consumer was identified as 2-hydroxy-4-methoxy benzaldelyde. Both root and leaves extract were active against, brine shrimp. The root extract were active against Neisseria gonorrhea, and superior to minoglycine drug used for control of sexually transmitted diseases (STD). Both root and leaves showed antibacterial effect against Escherichia coli, Salmonella typhii, Pseudomonas auriginosa, Bacilus subtilis, Staphylococcus aureus and Shigallae dysentrae. Escherichia coli was more susceptible while Salmonella tyhpii showed the least. Fungal bioassay carried out on Candida albicans and Aspergillus niger showed root extract to be more potent than leaf extracts.
Roots and leaves showed varied significant amount of proteins mineral vitamins and sugars depending on source. Mean concentration levels of minerals varied as potassium 11.34 - 32.05 mg/g, Sodium 5.61 - 24 mg/g, Magnesium 1.40 - 2.83 mg/g, Calcium 3.08 - 8.25mg/g, Iron 0.20 - 0.43 mg/g, Zinc 0.03 - 0.07 mg/g, Copper 0.003 - 0.06 mg/g, Manganese 0.64 - 0.05 mg/g, Cadmium and Lead were in trace amounts. Crude protein ranged form 4.35 mg/g - 21.8 mg/g, highest being from leaves. Vitamin varied as B carotene 4.35 - 21.81 ugg-1, Thiamine 0.78 - 3.70 mgg-1, Niacin 0.52 - 8.15 mgg-1, Riboflavin 0.62 - 2.45 mgg-1 and sugars, fructose 7.908 - 15.26 ugg-1, Xylose 9.17 - 18.70, glucose 2.40 - 9.0.
Comparison of basal diets for animal feeds, showed Mondia leaves had high crude protein and ash percentage of 20.25 and 16.98 respectively while dairy meal had crude protein and ash percentages 16.76 and 7.83 respectively. These results support traditional medical claim on use of Mondia whytei. The results show it has potential for human and animal health care. The chemical and phytochemical results have been used to reschedule Mondia whtyei products for quality assurance that are now being sold in leading Kenyan supermarkets.