In one case, the letter said, Lenore Zimmerman, 85, of Long Beach, New York, said TSA agents took her into a private room in late November to remove her back brace for screening after she decided against going through a scanning machine because of her heart defibrillator.

“Zimmerman said she had to raise her blouse and remove her undergarments for a female TSA agent,” the letter said.

The same day, Ruth Sherman, 88, of Sunrise, Florida, was asked about a visible protrusion from her waist band, which she identified as her colostomy bag.

She was “escorted to another room where two female agents made her lower her pants for an inspection. Sherman raised concerns that the agents would disrupt her colostomy bag, causing pain and potential damage,” the letter said.

A third woman, Linda Kallish, of Boynton, Florida, said that after she revealed she was a diabetic with an insulin pump in her leg, she was escorted to a separate room where she was told to remove her pants so the agents could check the pump, the letter said, without saying when that incident took place.

Last June, the daughter of Lena Reppert, 95, reported that TSA agents would not let her mother board a flight from Fort Walton Beach, Florida, to Detroit because her incontinence pad set off alarms, the letter said.

“We truly regret these passengers feel they had a bad screening experience,” the TSA said in its blog.