Vasovagal syncope /light headedness, digestive trouble

I have been on peritoneal dialysis for many years, usually some weeks are better than others. A symptom I had not experienced since around 2 years ago is somekind of vasovagal syncope reflex that I'm getting. I guess it is caused by all the blood pressure medicine I take plus the constipation I tend to suffer.

Generally I start feeling my feet and hands numb, I get light headedness, if I'm standing at that point I get shaky legs. It is usually accompanied by either flatulence or burping/acid. And of course, some sweating.

Has anyone of you experienced something similar? if so, what do you do about it?