what can this Mom do?

I think you do have options. If most of his problems are at night, you could try limiting his fluid intake a couple of hours before bedtime, and them having him empty before putting on any incontinence clothing.

I don't think a Foley is an option. They are not fun, and run the risk of inducing bladder infections.

Have you thought about a Texas catheter? It is in effect a sheath that slips over and has a tube connected to the a drainage bag. All external. Another option may be a soft clamp. There are several styles. I don't like them during the day. Just some thoughts. Sorry you and he are having so many problems.

Does the back brace preclude the use of more trimmer, slimmer bladder control pads that he could tuck inside the front of regular underwear? These are widely available in disposable and even some reusable styles in retail drugstores and online medical supply places, etc.

At camp, a toiletry/"shaving kit" -type bag could be used to discretely exchange dry pads for wet ones (perhaps with the help of some plastic bags) during trips to the lavatory. Establishing such a routine might prove helpful in the future if he were to go away to school for post-secondary education, and/or an extended vacation, or another camping-type  trip.

Good luck to you and your family.

Since bedwetters are generally deep sleepers I recommend using a bed alarm. That worked for me growing up. I found this link with some posted here: http://www.vitalitymedical.com/vitalitymed ical.storefront/4ac527cd0044e9e7271dd8b190 2c06eb/Search/Display