My consultant told me it is an age thing, I'm 72 and for the past 10 years or so have suffered from a hiatus hernia. The only food that I avoid these days are curries, pity because I love em to bits! I am now into a life routine. I eat early, about 6.pm and try to avoid eating anything else that evening. I bought an electric bed to help but it doesn't really help, good for reading in bed though. If I wake up with that 'burning sensation' I just nip downstairs and take a tablespoon of Peptac, from Boots. Its like Gavison, but half to two thirds of the price. For me, this works everytime. Sometimes if I worry that I will suffer that night I will take my dose before I go to bed. The consultant told me that apart from the elderly the other age group that gets this problem are a lot of young people who go to gyms to lift weights.
Sleeping in tents used to be a real problem for me, lying flat especially when I've had a pub meal and two or three pints, but I've learned how to deal with it. I do carry tablets but prefer not to use them, worries that they are potentially dangerous, e.g. strokes mainly. Not sure if this is factual but my GP told me to be wary of them.
What I do do however is before I go off hiking I get a load of large plastic straws, heat seal one end with a hot pair of pliers, fill the tube up with Peptac and then heat seal the other end. If I suffer on any night I just cut off one end and suck out the contents. It works very well for me. Problem now is I'm feeling guilty about plastics.
I used to get muscualr pains across my back as well. My solution was to buy a new rucksac, no longer a problem.