“Failed colonoscopy?”

I took moviprep Sunday evening and Monday morning for a colonoscopy Monday afternoon. It was 'inadequate with solid and fluid residue tapering the colonic mucosa' and only 'reached proximal sigmoid.' So after it failed my bowels started working and haven't stopped having loose movements since, basically water. I have tried to chase it with my specialist but was unable to get hold of her, so phoned my GP who has given me Loperamide. That was on Thursday. I took the full 8 I was allowed after each loose movement with no difference in the stool. I'm still going nearly every hour to two. I'm just wondering if I should continue using it as I'm usually fecally impacted and I don't think the moviprep has cleared it, so I'm worried it's going to cause bigger issues than being loose. I've taken another 4 in the last 24 hours but am worried about continuing. Should I keep taking the full 8 a day, cut it down, or not take more?

Background: I broke my spine 6 years ago and have a lot of nerve damage. I'm waiting for a neurologist currently. I have had issues with constipation for around 4 years and was first scanned as impacted around 2.5 years ago. Laxatives rarely work, or they're extremely slow working like this. I'm usually just in agony, feeling faint and vomiting when taking them. I'm supposed to take fybogel daily but am no longer able to stomach it, it just causes vomiting. I have to manually evacuate my bowels 90% of the time, but it's usually only one small ball per few days. I generally clear out randomly every 2 months or so. Suppositories (?) don't work as I think I manually evacuate the area they should work at.