In Texas, we have had a particular aggressive strain of the flu; I believe about a dozen deaths at last count. My wife and I, in particular, caught the flu in a bad way. We were laid up in bed for 5 days, nothing we ate stayed in our system for more than 10 minutes; we either vomited or had diarrhea.
At the beginning of the flu, I tried to stay on soylent but the vomiting commenced. I then changed to chicken broth and was able to keep it down but it went through my system very quickly. A little later I changed to chicken noodle soup and was able to keep it in my system.
At that point I decided to try soylent. The vomiting and diarrhea returned.
I called my doctor and explained what was happening. He said my intestinal tract was so irritated from the flu that it is likely that my body was not yet ready nutrient rich soylent and was (forcibly) rejecting it.
I am now back on soylent and my body is much more accepting.