Drain Pain, Why After 4 Weeks Post Op? Discharge A little Bit of Pink Fluid?

If you are still draining fluid a month after surgery, there is either a seroma (residual fluid under the skin), or perhaps a low grade infection.

I would culture the fluid and check for a seroma, by inspection, palpation and if necessary an ultrasound.

I might start some antibiotics after getting the drain culture and while waiting for the results.

There might be some buried suture material that needs to be removed from the area of drainage.

As you can see, the patient with a problem such as you describe needs to be checked and followed by her plastic surgeon to find out the cause and determine the appropriate treatment.

     Pain at the drain site can be normal, but have your plastic surgeon look at the site if you are concerned.

Some discomfort around a drain or drain site  may be to be expected after tummy tuck surgery. However, for accurate advice ( and to rule out complications such as infection) or real reassurance,  your plastic surgeon will be your best resource.  In person examination will be helpful.

 Best wishes.