Even companies that sell $9 billion worth of diapers have to respond when angry mothers post photos of their babies' irritated bottoms on Facebook.

Pampers officially rolled out its "Dry Max" Swaddlers and Cruisers in March, and the revamped diapers have already absorbed praise from parenting magazines and blogs. But a Facebook page opposed to the new diaper found 2,500 followers in five months, as parents went online to complain about leaks, blow-outs and, more ominously, painful sores that followed a switch to "Dry Max" Pampers.

Pampers says its diapers don't burn baby bottoms. The company says it monitored 300,000 diaper changes over six years to make sure the new nappies are safe.

"There's no evidence, from the people that called us, that a single baby has experienced a chemical burn as the result of Pampers with Dry Max," Pampers spokesman Bryan McCleary said.

Still, the Consumer Product Safety Commission is investigating more than a dozen complaints about Dry Max, including one from Joanna Ravlin Dye, a mother of three in Albert Lea, Minn. Dye said Dry Max Pampers left her 2-year-old Bridget screaming on the changing table.

"They're ... denying that mothers and parents know their own babies and are smart enough to know that it's not a normal diaper rash," Dye said.

CPSC spokeswoman Patty Davis said the federal safety agency will "be looking at the product's role in any type of incident or injury."

Pampers, a marquee brand of Procter and Gamble, knows it has to tread carefully, given the fiercely protective customers it's dealing with.

"Obviously, our hearts go out to every baby who experiences diaper rashes," McCleary said. "We take these things very seriously. We want to hear from people. This is one of the most thoroughly tested products, since we invented disposable diapers in the 1960s."

Parents were complaining about the new diapers before the company even announced the change. Some were perturbed when Dry Max diapers started showing up last year in the old packaging. Pampers billed them as twice as absorbent and lighter than their predecessors, but as any parent knows, tiny differences in diapers can mean the difference between a comfortable and absorbent fit, and a leaky, rash-inducing mess.

In December, Rosana Shah, of Denham Springs, La., put one of the new Pampers on her daughter. Within hours, the girl's bottom was bright red. Shah got nowhere complaining on the Pampers website, so she created a Facebook page demanding that Pampers bring back the old Cruisers and Swaddlers.

Such negative reviews prompted Ad Age magazine to describe the diaper rollout as a marketing misfire akin to New Coke.

McCleary said the factory started shipping diapers before the company was able to prepare customers for the change. "Looking back on this, we feel sorry for confusion that we may have caused during the early shipping of the product," he said.

Millions of the newly designed diapers have been snapped up since Pampers Dry Max officially debuted on March 15. Shah said traffic on her Facebook page has "skyrocketed."

"My 4-month-old is still healing from his blisters that are now scabbed over," one mother wrote. "There is NO WAY that this diaper is safe for anyone," wrote another.

Parents have even posted forensic-style images of dissected diapers and side-by-side comparisons of the old diapers with the new ones, marked up with arrows and exclamation points. Then there are photos to make any parent cringe: baby bottoms with bright red welts, rashes and oozing sores.

Pampers has fought back, with a vice president addressing individual concerns on the Facebook page and vouching for the company's scrupulous testing of the diapers on babies. The company also set up a toll-free number, 1-877-256-3265, for parents with Dry Max questions.

McCleary sees the advent of social media as "good and bad" for consumer product companies. "The good part is, you're able to get real-time information to people,'' he said. "The challenge is, it can be very difficult to get the correct information out in these circumstances."

Dye, the mother in Albert Lea, said she's convinced that the diapers are unsafe. She bought a box at a store in Burnsville in mid-March. The second time she used one on her daughter, it sprang a leak in the night. By the third one, Bridget had raised sores on her bottom that started to bleed an hour later, Dye said.

Then she went online and realized she wasn't alone. "That's too many children for it to just be a fluke," she said.

James Eli Shiffer • 612-673-4271