I can tell you from my own experience.  No one wants to hear the word colic spoken on their farm.  Even though as much as you care for your horses, it happens sometimes.  I always look when I go by my paddocks to see what my horses are doing. 

It is only natural for a horse to roll...Especially after they receive a good Wash off.  I have been so proud of my good wash jobs and look at how pretty they look...all brushed and clean. Ha! One good roll and its all over.  But when a horse rolls and carries on for any length of time,  it is not a good sign and might be colic.  I also worry when they are down and will not get up for a while.  Sometimes the are just sunning and sometimes they may not be.  It is something that has to be watched. 

Colic is responsible for more deaths in horses than any other disease of horses.  Out of every 100 horses, 4 to 10 of those horses, on average, will colic during the year.  Fortunately, 80% of those colics are called simple colics because most horses respond to medical treatment or get better without any treatment. Only 2-4% of colics are severe enough to require surgery.  If you have a horse that has developed colic in the past, that horse is three times more likely to colic again than a horse that has not previously had an episode.  Although all breeds can be affected, Arabians and thoroughbreds seem to have an increased number of colics compared to other breeds. Diet can play a role in colic as course fiber or course roughage with low digestibility can lead to impaction colic. Sometimes too much grain can cause colic.

Since my horse farm is in Palm City, Florida, sand is a constant problem. 

It is always a good thing to have emergency numbers of more than one vet posted at your barn for emergencies.  I have experienced the problem and scare of not getting a vet in time.  No matter when colic happens, it seems that it is always best to have several contact numbers available to ensure immediate help.