19 months after tummy tuck I’m severely constipated. Could my intestine be kinked, twisted during surgery so stools can’t pass?

The change in bowel movements may suggest something else unrelated to a tummy tuck.  If there has been previous abdominal or pelvic surgery or hernia repair was a part of the tummy tuck, there may be another dynamic other than nerve regeneration.  I would return to the plastic surgeon if concerns persist or worsen as the plastic surgeon can recommend something as simple as an OTC medication or high fiber diet for relief.

so you should be checked by your primary care physician and possibly a gastroenterologist as it sounds like you're doing everything you can to minimize your symptoms.