Continuing soft to runny poop

[gentfamily]

I have three rescue guinea pigs that I've had for about a year now. One of them for three or four days has had really soft poop and one day very runny. I have cut out all greens and withheld kibble for 3 days. Soft poop seems to be a tiny bit better but now a second guinea pig is having the same problem.
I have Oxbow Critical Care and I have given one tablespoon mixed with two tablespoons water twice a day that the three guinea pigs will eat as if it were a treat.
All are still active eating hay and drinking plenty of water.
Their house is a two-story 2x5 C&C cage. I use fleece as a liner and I have microfiber towels in the areas of the cage where they eat and sleep to provide extra comfort. Nothing has changed in the year that I have had them. Temperatures have not changed they're not in a draft I have not changed the brand of hay or the brand of kibble I did not introduce any different vegetables that might have started this.
I could really use some suggestions on what I could try I haven't already done.
THANK YOU in advance for suggestions.
Carol

 

[Piggies&buns]

I’m sorry to hear this

You have done the right thing in stopping all fresh food. You do not need to stop the nuggets (kibble).

Switch from the routine weekly weight checks and instead weigh daily. This enables you to more closely monitor hay intake to ensure they definitely are eating enough (hay intake cannot be monitored by eye).
I would also suggest you add in some probiotic - benebac is used in the US - to help settle their gut microbiome.

If removing veg doesn’t help (if it is going to help it will do so within a few of days) or if it helps but poops then go soft again, then the next step is to see a vet.
Full liquid diarrhoea is considered an emergency requiring vet care immediately.

I’ve added some guides below

Wiebke's Guide to Poops
Weight and Weight Loss Explained: BMI, Weighing, Poos and Feeding Support Levels

Once the issue is resolved, you need to be very careful about reintroducing veg. I have added a guide below which explains how to do it

How to Introduce New or Reintroduce Regular Fresh and Dry Food Safely - The Rules

I hope they are ok.
Keep us posted