Sometimes kids regress in development, when under stress.

Wetting the bed, can happen too.

But I would look to the diet and see if there are triggers present there. Dairy and gluten are the two most common GI triggers in children. Dairy can cause bedwetting in some children.

Also too much sugar or fructose in the diet can cause bowel urgency. Actually 1 in 3 people have a fructose intolerance.
So since that is a bit easier to control, I'd try withhold candy, other sweets, fruit and fruit juices and see if things improve. Combined with stress, a fructose intolerance is hard for adults to manage even!

Apples and pears are the worst offenders and some people can remember not being able to drink apple juice or cider!
In fact many mixed fruit juices are also high in pear juice.

Little kids in US really chug the fruit juices. So see if that is the culprit first. The second culprit is gluten. Going gluten free is more complicated but also may be a culprit.