My experience
As I have slowly but progressively reduced my symptoms, it has become easier to see which factors make which symptoms better or worse. Something that has become very clear is that constipation is one of the biggest impact factors on worsening symptoms. Hence, conversely, resolving constipation is mission critical for reducing symptoms.
I will cover below how I managed to resolve this for myself, and then we will look at the potential mechanisms of why constipation and PD symptoms are linked. I will first explain my self-observations which lead me to this conclusion.
Although I don’t often suffer constipation very often anymore, I can tell when I have a large movement in my bowels, and when it is reaching my colon, due to the pronounced effect this has on my symptoms.
Firstly, the main tell tale sign is that my dopamine replacing PD medications won’t kick in to turn my symptoms off. I will either have to take lots of extra meds for them to work, or wait until the bowel movement has come and gone, in which case the drugs will suddenly start working a few minutes later.
Furthermore, the so called “off” states between the doses of the drug are markedly different in character to the states due only to dose wear off. The most noticeable impact is that the brain fog is a lot worse and of a different quality. I feel really zombified and “out of it”, as if there is a lack of oyxgen getting to my brain. Secondly, my freeze is a lot deeper, such that it is much harder to move, and I am more stiff and rigid.
Extrapolating this to constipation, and reflecting back on the time before I had resolved it. I can now see how the situation where the bowel movement is stuck in the intestines results in permanently needing much more of the PD meds for them to work, and hence also having more side-effects from them. The corresponding off-states in between doses will also be much worse.
So I suspect that it is the case that for many people with PD they are suffering greatly as a result of their constipation, and if they could resolve this, they could also note a significantly decrease in their drug requirements and simultaneously have less symptoms. The good news is that this is fixable.
hOW i FIXED IT
The modality which most helped me the most with was when I started doing the belly position of Block Therapy once, for just a couple of minutes, daily.
This can be done with a rolled up towel instead of the block, and start by doing it on the bed, rather than the floor, as this is gentler.
Warning, this simple exercise can have powerful results. The first day I did it, I had to rush to the bathroom urgently three times, and had a good “clear out”. I also experienced significant hot flushes, and realized just how cold my body had been for years. Ever since that time, I hardly miss a day of having a bowel movement.
Another strategy which I found could have similar benefits was using Smovey Rings in massage mode on the belly, but doing the rocking motions to make them vibrate can be very tricky when symptomatic, because these types of motions are so difficult for people with PD.
Other things which I believe have significantly helped include restoring diaphragmatic function, again principally through the Block Therapy belly position, but also other breathing excersises, so that the full range motion of the diaphragm massages the gut and gets things moving. Eating many different kinds of fresh fruit, hydrating really well, including with chia seeds, and drinking prune juice, also help a lot. Movement therapies and dancing too. Stress reduction practices of all kinds.
MECHANISMS
I have some ideas as to why constipation increases symptoms so much, and also why it reduces the effectiveness of the medications. Firstly, recall that about 50% of the bodies production of dopamine is in the gut, and digestive system. In particular, dopamine is a key player in peristalsis, the pulsatile waves of contractions of the smooth muscles of the intestines which move things along. The gut may have “first option” on dopamine supplies to do its job, when required, in preference to sending supplies of the chemical building blocks of dopamine to the brain,
Thus when a bowel movement reaches the colon, it may temporarily demand more dopamine supplies, leaving not enough for the brain in people who are short of it. This would explain why I get more brain fog and feel zombified, when a bowel movement is due, and why I need more dopamine replacing drugs to get enough dopamine to the brain, or have to wait for the movement to have come and gone.
Likewise, if there is a blockage, or the intestines are having difficulty moving things along, the digestive tract’s priority call on dopamine may be permanently elevated, or the gut may be more demanding of limited supplies.
A second, related idea, is the role of the Dorsal Vagus nerve, that innervates the gut, in PD. Recall my theory of idiopathic PD is this is what happens when someone gets stuck in the freeze stress response. The freeze stress response is mediated by the Dorsal Vagus nerve, through signals arising from the gut to brain, which tells the substantia nigra part of the brain to stop producing dopamine.
So it makes sense to me that a bowel movement may stimulate the Dorsal Vagus in such a way that it inhibits the dopamine production in the brain. This would be especially the case if the Nervous System detects the presence of the bowel movement as a some kind of internal threat or stressor, for example if the intestines are inflamed in places (irritable bowel syndrome and leaky gut issues are also common in people with PD).