It looks like I have a stomach implant 15 days after CoolSculpting. Why is my stomach rock hard throughout my lower stomach?

The first question I would ask is if you really got Coolsculpting or a chinese copy which is not FDA approved.  If it was a knock off, there is no saying what exactly is happening.  If it is a genuine Coolsculpting machine from Zeltiq, this is very unusual and needs to be evaluated in person.  A very rare complication, perhaps less than 100 reported cases, is enlargement of fat after Coolsculpting.  I have never personally seen this, so I can't tell you if this is how this problem starts out.  The doc can call the company for advice if he needs to.

The area should have been massaged after treatment.  This helps increase the fat breakdown.  The tissue certainly can swell after this.  The swelling leads to the firmness. I recommend the use of compression to all of my patients to avoid excessive swelling.  I have my patents wear a binder that is neoprene that you can get for about 11 dollars on amazon so that this excessive swelling doesn't occur.  Although this process is not invasive like liposuction is does cause swelling.  The swelling leads to discomfort and the changes you are felling.