Adult briefs or commonly known as adult diapers can be found in many pharmacies and shops that sell home medical supplies.
I remembered my aunt used to buy some for my grandmother when she was bedridden for a few years due to stroke. My grandmother used to complaint how uncomfortable the diapers is and very hot. She refused to wear them and we will help her answer nature's call in the flat urine container which is commonly used in hospitals.
I read that Kendall brands is more comfy and super absorbent. I wonder whether it is breathable. That is very important especially if you live in a warm climax like here.