May I ask why people are against others going to the Caribbean? It doesn't affect you in any way. In fact, it gives you a greater chance to get into the med school of your choice. So many people talk about the horror stories, yet so many physicians in America graduated from there, and are practicing and earning the same amount as US grads!
We are generally about maximizing the chances of success. For people who want to go to medical school, there are essentially 3 options. US MD, US DO, and International MD.
Given that the end goal is to become a practicing physician in the United States, the best options are to go to a US MD school, and, if that is not possible, then a US DO school. Both of these have an extraordinarily high chance of allowing those who choose these paths to achieve this goal. Now, remember that the price of not matching is making it exponentially harder to achieve this goal and also comes with a large amount of monetary loss, both in terms of years lost to attending salary (if you are unmatched) and in educational expenses (which may be accruing interest if you took out loans, which, chances the hypothetical person did). If you take the IMG route, you run a much higher chance of not matching and entering this worst case scenario zone - a chance that is actually significant when compared to that chance for the USMD and USDO routes. Whether or not going Caribbean in general is a bad decision without respect to the fact that there are options (bear with me, I'll get to this part in a second), is something that is often discussed on these forums and if you do a search, you'll find a lot of threads with people arguing the point from all sides, os I won't address it here.
So let's assume someone can't get into a US MD school. The choice is US DO or IMG. Objectively, the more rational choice here (again, given our initial goal), is US DO, where you have a 99.something% chance of matching to a US residency vs a <90% chance (I won't list an explicit figure here because I don't actually know it offhand - I have heard percentages from 50-85% quoted on here depending on the school or whatever, but you can find the stats via NMRP or other sources that people have posted).
Now lets assume that someone isn't competitive for US DO. Should they go Caribbean? I will make my argument here that, no, you should not. What are the requirements to get into a USDO school? EC wise, that's the same for every medical school in the US and is easily "box checked" if you need to do that - just shadow a bit, volunteer a bit, be in a hospital a bit, you're basically
okay. Yes, I understand its more nuanced than that, but ECs are generally not the reason people don't get into a single MD or DO school in the US, so let's sidestep this point a sec. Statwise, you have a good shot at a DO school if you have a 3.25+ GPA calculated by AACOMAS and a 503ish+ MCAT, which is around a 27 on the old MCAT and is ~60th percentile or so. So 3.25/503. Let's work with that.
Let's start with GPA. If you come out of college with a lower GPA, and want to go MD, you have a few options. You can do a postbac, but this is expensive and doesn't raise your GPA that much. You can do an SMP, but that's risky and expensive. However, if you're applying DO, you have a third option - grade replacement. Strategically utilizing grade replacement over the course of a year can skyrocket your GPA. Take (and do well in) one to two semesters of classes that 1) you have already taken before and 2) will fully replace the grade you got before, and your GPA will shoot way up, definitely into range for DO competitiveness. What if you can't manage to pull your GPA up even after retaking (and perhaps doing poorly)? Well, if you're struggling with college level courses, you need to seriously consider how you will be doing in medical school classes, because I can tell you it won't be "excellently".
Now let's look at the MCAT. If you are scoring above the 50th percentile (500), you are at least somewhat competitive for a DO school. Might not be KCUMB or PCOM, but a DO school that will let you match with a very high chance of success in the US. Tried multiple times and still can't break that 500 barrier? Speaking as a medical student, the tests I've taken in the past year have been harder than any other tests I've ever taken in my entire life, including the MCAT. They are hard, they require a lot of intense preparation, they require strong critical thinking, and they cover a lot of material. And I haven't even thought about my Steps yet. If you cannot break the 50th percentile on the MCAT, do you think you are prepared for the highly intense high stakes testing environment that is medical school and beyond? I would say most likely not.
Finally, lets look at the last argument that people use to justify their decision to go to the Caribbean: time. I hear all the time "oh I don't want to take a year off and retake the MCAT or retake organic chemistry 1.5, I want to go to med school now!". Well that's great, but let's look at this from a not-super-short-term perspective. Let's look at your post medical school outcomes (again, keeping in mind that the goal is to become a practicing US physician). You can match into a categorical residency where you will become board certified. You can match into a preliminary residency with no PGY2 position and have to either reapply for the match, find an outside the match PGY2 position, or repeat your intern year. Or you can not match and have to do all of this again, with any of the options here a possible result of your next attempt. Additionally, keep in mind that the further you fall down this ladder, the harder it is to move back up, and the longer you stay at the bottom of the ladder, the less likely it is that you'll be able to climb it again.
Now let's go back to our scenario of Anxious Arnold and his desire to start medical school as soon as possible. If he goes straight to the Caribbean, there is a much higher chance than normal that he will either match into a prelim position without a PGY2 position (look at Ross's match list - there are an awful lot of prelims there, and Ross is one of the best Caribbean schools) or that he will fail to match at all. That already puts him a year behind because he's going to have to apply to the match again, and, unfortunately for him, Caribbean graduates who fail to match the first time have two red flags going for them in the eyes of US program directors. He's going to have a very difficult time climbing that ladder in either circumstance. He could match into a categorical position, but he has a much lower chance of doing so than his US counterparts. He could also have to repeat a year, which would put him a year behind (again, much more likely in the Caribbean than in the US because of how they structure their program), or, worst of all, he could fail out and be heavily in debt with no career prospects. So in this case, if he decides to jump the gun and go straight to the Caribbean, he has a high chance of having to start his career a year later anyway (if at all) in addition to the other risks I've already talked about. However, if he takes that year up front to improve his GPA or MCAT or whatever and goes to DO school, he is far, far less likely to run into any of those other problems and thus will be much more secure in attaining his goal.
Now, (and if you're really sensitive or whatever, this next part might be a bit harsh), I have said before and I will continue to say that if you cannot get into a single US MD or US DO school within several cycles of applying, you should not become a physician. Note that this does not include everyone who goes to the Caribbean. There are some who, if they had followed this advice, could have strengthened their application and gone to a US school, or a select few who, like you, turned down a US MD (???) school for a Caribbean school. Some of these people succeed, some of them do not. More do not than would have had they gone to a US school.
Another argument I've heard is that people who could have gotten into a US school will be the ones who do succeed at a Caribbean school, but I don't think this is true. US schools (both MD and DO) are designed to, if you get in, get you to graduation and residency, because if they don't, then licensing bodies put them on probation or shut them down. Caribbean schools don't care if you fail or pass, so these people might still actually fail out of school or fail to match (both of which put you more or less in the same boat) if they don't have the support system of the US school. Thus, if you are the type of person who thinks they would succeed in the Caribbean, you are also likely to be the type of person who could get into a US school, so why not just go to a US school?
I hope I haven't left anything out. I spent a good amount of time typing this that I should have spent learning about kidney disease, so I hope it's clear. Anyway, these are all of the reasons why I never advise anyone to go to the Caribbean. Not because it dooms you to failure, but because it just doesn't make sense.