I am trying something that others suggested for garlic intolerence. I purposefully ordered a dish that I knew had garlic in it at a local restaurant. Before it arrived I took 3 charcoal caps (to prevent gas). As I started to eat the meal I took 3 Beano tablets (which supposedly help digest garlic). After eating I took 3 more charcoal caps. Made sure to drink plenty of water with all of this. The outcome was really good. Instead of lots of abdominal cramping and killer gas almost immediately after the meal I just felt very full. Had a bit of gas around bedtime but nothing painful and not the usual belly bloat. In the morning I had a very small bit of gas but no bloat or urgency to run to the loo. Around 10:30 am, a couple hours after breakfast, I had one slightly loose stool but no diarrhea. And that was all. I was able to be out and about without worrying where the nearest toilet was. The following day I had two morning BM's that were a bit loose but nothing else. No cramps, urgency, gas bloat or diarrhea.
I should also mention that I take one Questran sachet in the morning before breakfast and one Imodium tablet before dinner. It's very early days but I'm hopeful this will help. It's so hard to avoid garlic. It's in everything and even if you ask for dishes without it at restaurants the chances are there will be some anyway in one of the ingredients that the chef doesn't know about. I'm going to be on the road in France and Spain in a few weeks so it would be great if this prevents having to make pit stops every few hours along the way.