Oh my thats sad;
Just keep up the water intake, if he realy cant take it, he can stop tabs for a couple of days and start back gradually.
Other things you can try for toxins are psyllium or charcoal, not sure the quantitys though. You can also try an enema to clean out the colon as a good colon cleanse can get rid of toxins fast. Hopefully someone else can come up with something else you can try.
Hope this helps
JOYCE