Two children in Tennessee were recently hospitalized because their families could not find the specific formula they need during a nationwide shortage that has grown more acute over the past month, sending parents frantically searching for interim solutions.

Both children have short bowel syndrome, which prevents them from absorbing nutrients properly because part of their small intestine is missing, according to Dr. Mark Corkins, a pediatric gastroenterologist at Le Bonheur Children’s Hospital in Memphis, where the children were treated. Their condition requires special dietary interventions.

One of the children, who is preschool age, was hospitalized at the end of April and is still in the hospital. The other, a toddler, was hospitalized last week and has since gone home.

Each child needs an amino-acid-based formula and had been taking EleCare, a product manufactured by Abbott Nutrition, which closed its plant in Sturgis, Michigan, and voluntarily recalled some of its products in February after at least four babies who consumed them were hospitalized with a rare but serious bacterial infection. Abbott reached an agreement with the Food and Drug Administration this week that enables it to resume production in the Sturgis plant in two weeks. Products from that plant may reach shelves within two months.

Abbott’s products account for 48.1% of the market share of baby formula, according to an IBIS World report in 2020, making it difficult for the industry to quickly ramp up supply. Combined with pandemic-related supply chain woes, the recall was a catalyst for the drastic nationwide shortage.

Corkin called it the worst crisis he had experienced in his medical career. He said there had recently been an increase in calls from families whose children have disabilities or medical conditions that require them to be on specific formulas.

The two children hospitalized in Tennessee, whose families have declined to speak with the news media, did not respond well to several other types of formula that Corkins tried to put them on. Other formulas have proteins that need to be broken down by a person’s body, but the protein in EleCare is basic amino acids.

“They don’t have to digest it; they just absorb it,” Corkins said.

On the other formulas, Corkins said, the children experienced dehydration and diarrhea or had too much output into their ostomy bags. To keep them healthy, he had to put them on IV fluids and nutrition, which he said carried the risk of infection and did not give the stomach or intestines the optimal level of nutrients.

Other short-term risks of not being able to get proper nutrients, he said, include elevated levels of potassium and salt in the blood, which can cause heart or kidney complications. Corkins said he was also worried about the long-term impact on growth and brain development.

“Even if they’re not stooling out and getting dehydrated and having trouble with fluids, I worry if they’re getting enough nutrition that they’re going to grow like they should,” he said.

On Tuesday, House Democrats proposed an emergency funding bill that would provide the FDA $28 million to address the current crisis and prepare for future shortages. The legislation is expected to reach the House floor this week.

The shortage has been especially challenging for low-income families and those whose children have restricted diets and disabilities. Some parents have considered watering down formula to make it last longer, but doctors have warned against doing so because it could lead to serious health problems. The Department of Health and Human Services has put out an informational sheet with resources to help families find formula.

Nurses and doctors in Corkins’ hospital are working with patients to safely alter formula recipes and perform follow-up examinations and tests on the children, he said. Many of the most affected children have short bowel syndrome, enzyme defects that affect the way they can break down food, or other intestinal conditions.

Corkins said families unable to find formula should reach out to their pediatricians and closely monitor their children’s health. For now, he said, hospitals around the country will most likely need to take stopgap measures that will not be ideal for children.

“There’s enough of these kids out there that we’re not alone,” he said. “We’re going to stumble along until the formula’s back.”

This article originally appeared in The New York Times.