Your son.. his symptoms say probably a mitochrondrial disorder to me.. has bowel issue (severe constipation I think is more common in mito disorders then ME thou it does happen in us too) and then there also his hearing issue (very common in mito) . Thou ME seems to also be a mito issue, I think one can still see the signs that more mito stuff is going on then typical ME cases.
I know you say your son understands pacing but I personally from what he's done, I dont think he has fully understood it and the consequences of not doing it properly. Usually when one is pacing properly and feeling better, one knows to slowly increase activities over time, one takes in consideration how much one did the day before and how much one will be doing tomorrow, its not just about how much one feels one can do right now. With good pacing, the waters are always being tested one could say before diving in the deep end and just hoping for the best.
If one is feeling a bit better, one may go for a 10min walk (or only increase activity by several minutes, depending on how severe someones ME is) ... several days later it may be a 15min walk instead of 10mins if that 10 mins didnt make one sick etc. To suddenly go for a 40min walk and then play football on top when your son hasnt even been well enough to go to school this year, is a MASSIVE leap and not pacing. (I think most of us would of been shocked to read he went and suddenly just tried to do that.. understandable thou if he didnt know).
Doing something like this can someone MUCH WORST and they may not recover from it, a huge increase like that can send someone into a worst baseline with this illness. I really really hope your son hasnt done this! His best chance of recovery is probably in his younger years so its important he takes great care with activity increases so that he keep heading in the right direction for improvement and not mess it up. (most of us have experienced really messing up our improvement at some time or another).
Sudden improvements can be uncommon and should be really treasured like gold and at those times we need to be very careful not to blow our sudden turn into better health by overdoing it and loosing the improvement.
I know you have some money issues but its also probably essentail to get him to a ME specialist, otherwise he could end up having this illness for life and need care, going to specialist greatly probably increases his chances of maybe recovering. The sooner you do this, probably the better. If he gets sicker he may be too sick to fly him anywhere at all to get help so you need to do so now (many of us are too sick to fly).
I could only say bad things about his doctors from the things you've said, sounds like he hasnt had enough tests!!. and extensive illnesses should be considered as a whole.
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I also dont think his current bowel program sounds too good with having to take enemas, to me says he probably hasnt had things managed as well as they could be.
Both me and my daughter have had severe bowel issues to the point where we needed daily enemas but we both are off of these with good bowel treatment. (my bowel issues even prolapsed my bowel at one point cause I hardly had any peristalisis, my daughter has a spinal issue so had her bowel affected throu that). Good bowel specialists have both of us not needing enemas no more (we both had difficult cases which werent easy even for the specialists, the normal bowel laxatives did nothing at all for me at even large doses and in combos.
My daughter originally had to be hospitalised a lot for her bowel before this was sorted due to impactions etc, it took them ages to work out her treatment (she had to go onto 3 different things for her issue).
Both of us due to the treatment we had for this, we both have better functioning bowels and I dont even need to take anything or mine any more (I do think she's doing much for hers now to and may not now be havin to take meds). Im just telling you all this as there may be some room for improvement there. (I suspose that if your son does have mito disorder that treating that may help his bowel too?).
I wish you and your son the best, I really hope he starts to improve from that crash soon. (Ive had severe crashes last 3 weeks, often crashes that bad will leave me at a slightly lower baseline then before). Make sure he is taking it very easy, he should take care not to exert himself at all if he can still he starts improving from that crash, even if it means not doing basic things.