I assume none of us here belongs to any medical profession, that's why we can only guess.
MHO is that it doesn't make any sense to cleanse the colon and continue to eat same amount of food plus psyllium from the first day of cleansing. It doesn't make much sense to me to copy somebody's experience and wonder why it didn't work or worked differently. Listen to your body and start with smaller amount of "recommended" dose at least.
Remember Herbalife? It helped me to cleanse but I never saw any ropy substance. I used Paraway Pack that containes parasite cleanse and fiber ( including psyllium in the right amount) and lax. tea. No plagues though I felt great! By the way they recommend it only twice a YEAR. It doesn't mean somebody didn't have an opposite experience.
Common sense dictates that if you have a side effect, even one, reduce the dose, review your diet, or just stop it.It's not for you.