Q.Rhubarb Problem.
Last year lots of rhubarb stalks had black puncture marks oozing sticky liquid. #1.What causes it? #2 Is it safe to eat the stalks with this problem?Binned them all last year. #3 How to prevent the same this year?see a few stalks coming up. Thank you

Certified GKH Gardening Expert
Unfortunately, your photos did not come through. I am unable to see the damage. It sounds like an insect has pierced the stalks causing damage. I would use insecticides (natural, if you prefer) and fungicides to correct any issues left behind be the insects.
It will, likely, be safe to consume. Less dangerous than the plant, itself.
These articles will help:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/garden-how-to/info/homemade-fungicide.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides
https://www.gardeningknowhow.com/edible/vegetables/rhubarb/harvesting-rhubarb.htm