Q.bumps on courettes
My sister has bumps on her courgettes. What is it and can I heal it? And are the fruits edible still? Help greatly appreciated. Sister lives in Wales.

This can be caused by several things. Most are plant disease related and they cannot be corrected. The squash is safe to eat though, but you may find the flavor to be off.
This article will have more information:
https://www.gardeningknowhow.com/edible/vegetables/zucchini/bumps-on-zucchini.htm