Hello - hens do periodically go through natural periods of rest from laying but these are usually not very long when it comes to hybrid breeds. Can we ask what you are using to worm the hen with, we always recommend Flubenvet as it is a licensed poultry wormer and proven to destroy internal worms. Hens may stop laying for a variety of reasons, it sounds as if you are providing all the necessary dietary requirements, again we recommend a good quality layer pellet throughout the day with the occasional treat of some fresh greens such as broccoli stalks or cabbage leaves, provision of oyster shell for additional calcium.
Some hens can become blind or internal layers, this means they lay eggs internally, these can be naturally reabsorbed but if they do become infected can lead to an egg peritonitis. You would notice your hen becoming sick and unwell in this case. Click here for more information.
We would suggest you check the worming as a very high burden can stop a hen from laying, you can check this by sending us a droppings sample and within 48hrs we will give a result of the worm egg and coccidiosis count. Click here for more details. Also previous disease challenges such as Infectious Bronchitis can cause damage to the oviduct (egg laying tubes) which can cause laying problems, any stress such as predators, terrible weather, incorrect diet etc can all be factors. If all the environmental things are fine then you need to look at worming or possibility of internal/blind layer.
If she is happy and healthy in other respects then you may just need to wait and see. Her runny poo may benefit from a dose of Beryl's friendly bacteria, this contains over 200 friendly bacteria and will help to restore normal gut flora.
We hope this helps.