I am an impatient person. I'm one of those who'd rather drive an extra half hour to avoid construction just so I can be moving the whole time. When I have a problem, I have to do something about it, even if that something will in no way change the outcome. It's a pathology.
So, after my doctor informed me that he thought the inflammation in my colon could be causing my pain, and that I should see a vascular surgeon (whom I see next Thursday), I started to think. I know a lot about physiology. I teach it, as well as pathophysiology. How could we possibly determine whether colonic ischemia is causing my pain? For those of you who aren't physiology buffs, let me explain ischemia. When you do any kind of high-impact sport, and especially in running given that it is a constant motion, your blood shunts to your legs. There is an 80% reduction in blood flow to the GI organs to compensate for the extra oxygen demand needed in the legs. This happens in anyone who runs. My doctor is theorizing that, in my case, the amount of blood shunted away from my colon is excessive, causing ischemic pain (the kind of pain that results from lack of oxygen). He has the idea of them giving me a medication that will vasoconstrict the vessels feeding my colon (a sort of induced ischemia) and then seeing if my symptoms occur.
There are two ways I can think of that would allow that to be done. The first would be to give me some potent alpha agonist vasoconstrictor (excuse the pharmacology talk), such as Vasopressin. Its action is direct and very powerful constriction of the arteries. Problem is, it's not colon specific. So if they gave me that, it'd constrict the vessels to my heart, my brain, etc. Not sure I like that idea. The other idea I had was that they could dilate my arteries, have me run, and see if my symptoms DIDN'T occur. This could be done with a potent arterial dilator such as Nipride, which is often used in ICU patients in hypertensive crisis and those recovering from open heart surgery. The problem, again, is that it wouldn't be vasodilation specific to my colon--all of my arteries would dilate and my blood pressure would go very low, making it difficult, if not impossible, to run. Then I thought--hey, they could give me an IV fluid bolus with the Nipride while I'm running to keep my blood pressure up. Then I thought--what doctor would ever actually do that?
So, since I'm waiting to see the vascular surgeon, and I can't bear the thought of waiting without DOING anything, I devised an experiment. I completed it last night. I came up with an indirect way to determine if (maybe) the pain I experience running is the result of ischemia or the result of impact. The idea was to get on my bike (on the trainer), get my heart rate way up, and see if I had the pain. If the problem is blood flow, then it should happen on the bike, right? Realizing that more blood is shunted away from the colon in running than cycling due to the impact, I decided I needed to get my heart rate up REALLY high on the bike, as high as I could get it. Surely, if ischemia is the problem, that ought to bring on the symptoms.
So I did it. I haven't been on my bike since August. I forgot how difficult it can be to get your heart rate up on the bike. While running, my max is around 200--and so I think I'm probably around 180 or so on the bike. I spun for five minutes and my HR was just around 120. No pain yet. I decided it was time to get my heart going. I put it in the highest gear, came out of the saddle, and began "climbing." I did this for a few minutes, and my heart rate was just 160. But I was dying! However, no belly pain. I then spun another few minutes, and climbed again. This time, I got my heart rate up to 170. My legs were on fire, I was gasping for air, and all I wanted to do was stop. But no belly pain. I spun easily a few more minutes, and gave it one more go. I actually got my heart rate up to 180. And I held it for about two minutes. It was awful, and my daughter Amelia became very concerned watching. Throughout all of that--my abdomen never hurt. At all.
So, signs were suggesting that the problem is impact rather than blood flow, but I still wasn't totally convinced. I got on the treadmill. I ran as slowly as I possibly could--at a 12 minute pace. My heart rate barely cracked 100. However, after half a mile of this, I started getting the abdominal pain. By one mile, I had it on both sides. By 1.25 miles, it was radiating around my back. At a 12 minute pace, and an average heart rate of 110. Just enough impact to bring it on. I highly doubt that my heart rate of 110 caused any major ischemia to my colon.
So, what do I do with this information? I don't really know. I'm still going to see the vascular surgeon, but I think my experiment is a pretty good indication that we're not dealing with that kind of beast. So, what is it?! I have no idea, but it's not an overuse injury. I have had plenty of those. This one came on in the first run after a 3.5 month layoff. It's literally like my organs "catch" on something as I run, causing this severe pain.
Oh, I also ran 11 miles today. It hurt....both sides. If anyone has any idea what this could possibly be, please tell me....I am a much better runner than cyclist.