Tram Nguyen has used restroom floors, the grass at city parks and the back of her van to change her 7-year-old daughter's diapers.

Her daughter, Sadie, who was born with a chromosomal abnormality that limits her mobility, has outgrown the infant changing tables in most public restrooms.

"It's disgusting and undignified to have to lay your daughter on a bathroom floor," said Nguyen, a former retail executive and stay-at-home mother from Minneapolis. "My daughter needs to get out in the community, and not having a safe, private place to change her diapers is a major obstacle."

Nguyen has joined a burgeoning campaign to make public restrooms more accessible to larger children and adults who have difficulty using toilets because of their disabilities. They are calling on the Legislature to enact a proposed law that would require adult-size changing tables in public restrooms — a change that would help reduce the isolation that often comes with living with a disability.

The campaign is being led by a group of Minnesota mothers of children with disabilities who are fed up with hunting for sanitary ways to change their kids. The dearth of accessible restrooms means they are often pushed to the margins of public spaces — forced to change and clean their children on floors, cars or behind trees at highway rest stops. When winter comes, many stay home because it's too difficult to find clean, private changing stations.

These mothers have launched a Facebook group, called Changing Spaces Minnesota, that helps people with disabilities navigate the often-maddening search for accessible restrooms, and alerts them to places with adult-size changing tables. They are also reaching out to public institutions — including hospitals, libraries, parks and stadiums — to encourage them to install the tables. Fewer than two dozen buildings statewide have them, they estimate.

Their longer-term goal is to get height-adjustable, adult changing tables in every public restroom in the state. They say that would benefit a broad swath of older and disabled Minnesotans who have difficulty using standard toilets.

"This is about human dignity," Sarah St. Louis, an architectural project manager from Shorewood, who has an 11-year-old son, Ezra, with physical and cognitive disabilities brought on by a traumatic brain injury at 20 months old. "Tomorrow, you could experience your half-naked body being put on a dirty public restroom floor to be changed because you never thought that having a sanitary, safe, adult-sized changing table was worth it or needed."

Their efforts have reignited a broader discussion about equal access for people with disabilities.

Julie McDonnell, a schoolteacher from Bloomington, has a 5-year-old daughter, Macy, with significant developmental delays caused by a rare chromosomal abnormality. At nearly 40 pounds, Macy is already too heavy for the ubiquitous baby changing tables in public restrooms. When they go to her older son's soccer games or other public places, McDonnell said she has no choice but to change Macy on the floor of their wheelchair-accessible van.

As a result, McDonnell said they have to schedule social outings around Macy's bowel movements — and often skip events with other children.

"I refuse to change my daughter's diaper on the floor of a public restroom," McDonnell said in written testimony in support of the proposed bill. "Clearly this is disgusting and unsanitary, but it is also an invasion of her privacy. ... Macy, as well as everyone with a disability, deserves to have dignity and respect while using the restroom just as those of us without disabilities do."

Steve Utgaard, a cafeteria worker and volunteer caregiver from Maplewood, said he stopped taking his teenage friend with cerebral palsy to parks because of the same reason. Sometimes he would have to search for hidden areas in parks — behind trees and bushes — to change his friend's undergarments. Even then, people occasionally stop and gawk.

Once, Utgaard said that he was forced to change his friend in the utility closet of a cinema after discovering that the theater lacked a wheelchair-accessible bathroom. "My friend was humiliated and so was I," Utgaard said. "It's crazy in this day and age, but this is what life is like for a lot of people with disabilities."

The proposed bill, which this week passed the Senate Labor Committee, would change the state's building code to require adult-size changing tables in the public restrooms of all newly constructed buildings, as well as modifications to existing restrooms. The costs range from $2,000 for free-standing tables and up to $30,000 for more sophisticated, wall-mounted tables that can adjust for a person's height.

Disability advocates maintain that the cost of adding the tables would be more than offset by increased revenue from customers with disabilities and their relatives.

Five years ago, Linda Hood of Woodbury contracted a rare illness known as Guillain-Barré syndrome that attacks the body's immune system. The former clinical scientist and triathlon competitor, who once climbed Mount Kilimanjaro in Tanzania, became paralyzed and less able to control her bowel movements. Overnight, she discovered that most public facilities, including the hospitals she visited for medical appointments, were inaccessible.

"This one change [to add adult-size tables] will bring thousands of people out of their homes. And when businesses realize that, they're going to wonder, 'Where did all these people come from?' " said Hood, 64. "Right now, if you have to lay on a dirty bathroom floor to get changed, it makes you not want to go anywhere."

On a recent afternoon, Nguyen was visibly elated after she discovered an accessible changing area in a family restroom at the Mall of America. The room had a height-adjustable table that enabled Nguyen to transfer and change Sadie without having to lift her 60-pound frame — which can be a strain on Nguyen's back. The padded table also had a strap and a railing to keep her daughter from rolling off as she was being changed.

"This is like Christmas!" Nguyen said, after posting images of the changing table to the Changing Spaces Minnesota page on Facebook. "This opens up a whole new world for us."