The manager, whose name Knull did not recall, upgraded the couple to a luxury room where they stayed the following night. But Knull said she began to feel worse and Schwander got sick, too. They endured intense stomach cramping and diarrhea. She had blood in her stool. His eyes wouldn't stop watering. They awoke to Schwander drooling a lot and a sweat-soaked bed.
"I had sopped his chest up (with drool)," Knull said. "I was sweating so hard my eyes were tearing. My vision was blurred. ... My head was getting dizzy."
Knull said she thought back on what she had seen days earlier: A maintenance person spraying palm plants that covered air conditioning units just outside their room.
"I wondered if someone sprayed our unit," she told CNN. "They are always constantly out there taking care of the plants. We saw them out there with bug sprayers."
The couple grew angrier as their symptoms worsened. Knull said her stomach cramps were so bad it felt like "chainsaws going through my insides."
Knull said she went to the front desk and demanded to know what was going on. "We asked for paperwork, for everything and they refused to give anything to us."
A couple days later, the couple decided to cut their vacation short and fly home at an extra cost of $600.
The flight home was painful, Knull said. When they arrived at a stopover in a New York airport, they raced to the bathroom.
On their final flight home to Denver, Knull said she was buckled over from the pain of stomach cramps.
They spent the next several days at home, drinking water and juice, and their symptoms began to ease. They were examined by their respective family doctors who, according to medical records Knull provided, suspected the couple had been exposed to organophosphates.
Organophosphates are man-made chemicals typically found in pesticides, such as ant and roach spray. It can be absorbed through the skin, inhaled or eaten. Exposure can cause increased saliva, tear production, diarrhea, nausea, sweating, confusion and other symptoms, according to the National Center for Biotechnology Information. About 3 million people worldwide are exposed to organophosphates every year, accounting for 300,000 deaths, the NCBI reports.
Exposure to organophosphates can cause respiratory problems or failure, said Dana Boyd Barr, an Emory University professor of exposure science and environmental health. She's studied organophosphates for 30 years.
Typically those who are poisoned by organophosphates seize or salivate excessively, she said.
Knull and Schwander's attorney, David Columna, and a Florida-based lawyer who often works with him, John Urban, told CNN that in the Dominican Republic there is no discovery process or jury trial. When a lawsuit is filed, it's up to a judge to decide when a hearing happens during which both sides present arguments. Then the judge renders a decision. It's possible the hotel could settle with the couple, Urban said.
Knull became emotional this week reflecting on the people who have died. More than winning the suit, she said she wants to know what made them sick.
"Maybe that will help them," she said. "If talking about what happened to us helps find out what happened to those people -- God bless their families. They deserve answers."