Q.houseplants are turning yellow
Several of my houseplants are turning yellow from the tops down (leaves to the stem). They are not all in the same room & the bamboo is now hollow where it’s the most yellow & 1 stem goes all the way to the dirt – but not below. Help!!!

What types of plants are being affected? It would be easier for me to help diagnose if I knew the plant types since different plants have different requirements for water, lighting, fertilizing, etc.
How often do you water them - yellowing leaves could be due to over or under-watering. Feel the soil - if it's damp/soggy, you have been over-watering your plants. If the soil is bone dry, the plants are under-watered and need a drink.
Yellowing leaves can also be attributed to insect pests, lack of sunlight or being root-bound. I would recommend that you read the following article which will assist you in determining what is happening.
https://www.gardeningknowhow.com/plant-problems/environmental/plant-leaves-turn-yellow.htm