Can most people have second tummy tuck after 4 years?

If the doctor says they didn't pull you hard enough on the sides that means there is more to take out, so yes you can have a revision. 

There are no rules how much skin can stretch after 4 years. Detailed clinical evaluation is needed to determine how much skin can be removed and whether it will include all stretch marks. I you are considering second abdominoplasty you should seek a consultation with an experienced board certified plastic surgeon (or your first surgeon if you have good report), for detailed clinical exam and discuss your options. Good luck.

Wen proper planning is done before performing a TT and the procedure is properly executed, it is very rare to need a second operation, unless the patient gains or loses significant amount of weight. The lateral extent of an operation is part of the planning of the surgery. Sometimes the skin removal has to go farther towards the back or be done circumferentially to avoid excess on the sides. In this case the operation is called an extended TT or a belt dermolipectomy or a body lift. This is more than a TT and should be discussed with the patient in advance. From your description id seems that you may have required a more extensive procedure  than a standard TT.

A tummy tuck can be repeated if indicated or revised if a lesser improvement is needed. A plastic surgeon certified by the Anerican Board of Plastic Surgery should be able to guide you in your decision.

Without examining you or seeing photos its difficult to give specific advice but you probably don't need another full TT based on why you are describing, just a revision of the excess skin that remains. The only way to know for sure is to book a consultation with a board certified plastic surgeon near you to see what your options are. Best of luck!