Nothing in the world is a random incident. Everything is a result of a decision or a selection, either conscious or subconscious. The selection may have been made a moment ago or in the past, maybe in such a remote past that you have difficulties with relating to it.
Every effect has a cause. Chaos may seem random, without a pattern, but the pattern is always there. So it is with the decision or the chain of selections that lead to the current moment. It might seem that the result is erratic: you ate something gone bad or unsuitable to you and your stomach got upset. Big deal. In the material cause and effect world this seems applicable. In the energy world, there are no coincidences. Every Thing, whether you can see the cause or not, has a higher purpose hidden within it.
The healing practice described here is simple but may need some practice. You can do it while sitting on a chair or while laying in bed on your back.
As we, human beings, have moved quite apart from our ancient skills in self-healing, it is advisable to consult modern medical experts whenever in doubt.