This question is really difficult to answer. It depends so much on the individual.
People flunk out for one of two reasons:
1) They don't work hard enough
2) They aren't intelligent enough
The vast majority of students who are accepted have the talent to get through the coursework if they apply themselves fully. Others can possibly get by with minimal effort because they are so bright, but those are also the people who can be elite physicians if they do work hard. In other cases, I feel sorry for some students who seemingly study for 6-8hrs until the library closes every night yet barely pass or flunk out of the program, but not everyone gets to be an astronaut when they grow up if you catch my drift...
I go to Barry where the pod admissions process is fairly unselective (at least they were for my '09 class), but the classes have a fair amount of attrition because of that. It's nothing like the Carribean MD schools that might accept 400 and only have 150 still around 16 months later to take the USMLE, but my podiatry professors do owe it to the profession to make sure we have the scientific knowledge to be good podiatrists and they will fail you if you don't perform adequately. By the end of the third semester, my class probably did had about 30-40% flunk out completely and some others were sent to the extended 5yr program (which kinda means you might also be circling the drain unless you really take the hint and start working harder). Some people who went to undergrad at Hopkins or Harvard have failed, so you certainly do have to work hard. I'd have confidence in 95% of the graduates practicing podiatry to at least minimal standards, and that's the way it should be.
We have people doing a one year Biomedical Sciences M.S. degree in some of our classes for the first year (they take gross anat, histo, biochem, neuro, etc with pods). Most of the people doing that degree narrowly missed med school due to undergrad GPA, and roughly half of them will get in to MD/DO programs once they complete the M.S. with good grades (and maybe re-take the MCAT in some cases). The grades they get in shared classes aren't dramatically higher than the pod students, and they also have easier lab exams and more pressure to get "A"s so that they can get into programs afterwards. The good Biomedical Sciences students who eventually make it into MD/DO programs perform pretty similar to the better pod students.
Here at Barry's program, the first semester is pretty easy since they know you're getting used to a new city, but the next 3 semesters are fairly tough depending on your prior education, work ethic, and natural talent. You have roughly one exam per week, but midterms or finals weeks might be 6 or 8 exams in a two week period (maybe 4 of them really tough). Some friends and I sleep roughly 2-5hrs per night during those weeks except for maybe one night of 10hrs to stay sane.
