I'll suppress being pissed at morons trying to get high for the moment for some real discussion.
Taking loperamide in excess like that, especially in someone who has no tolerance to opiates, can cause a number of problems, none of which are enjoyable, funny or trivial. It should be noted that all opiates can cause problems like this, but using large amounts of loperamide carries the most risk for a number of reasons.
The following problems can occur:
1: Slowed or stopped bowel motility in an opiate naieve user will in some cases cause a bowel perforation. Symptoms will be extreme abdominal pain which gets worse with movement, sweating, vomiting, and an massive infection due to bacteria being released into the body. This requires hospitalization and in some cases results in death.
2: Toxic megacolon, this is a distention of the bowel which can lead to perforating the colon, septic shock, and a number of other serious problems, in many cases it requires removing the colon entirely.
It isn't fun in any case, there are other opiates available.