It sounds incredible but Mr Aaron Tay says he did not pee for nearly four years.
The reason? Kidney failure, which resulted in his kidneys not removing wastes and extra fluid from his body.
"I didn't need to go to the toilet; there was no urine at all," says the 37-year old, who had to go for four-hour dialysis sessions three times a week from 2004 to 2008.
Without urination, fluids began to build up in his body, leading to a host of complications, one of which was chronic heart failure.
"Water accumulated near my heart and caused it to be enlarged to almost double its size. The doctors said it was functioning at only 25 per cent," he says.
If he did not have an emergency kidney transplant, he was told, he would die.
It was the latest blow to the then 28-year-old, whose life had been a series of medical calamities.
Several years earlier, he underwent chemotherapy for lupus, an autoimmune disease he was diagnosed with when he was nine. Then there was a cancer scare with a tumour in his nose. He is also thalassaemic, and battled depression as well.
Fortunately, one of his younger brothers stepped forward to offer one of his kidneys. The transplant in 2008 gave him a new lease of life.
"My heart is restored, my kidney function is restored and I pee normally," says a trim and healthy-looking Mr Tay.
Now running a financial advisory practice, he is happily married to a renal nurse who looked after him when he was a kidney patient.
The eldest of three sons of a teacher father and a nurse mother, Mr Tay's troubles began one night when he was eight.
"I remember I was watching a Chinese serial on Channel 8 when my ankles started to swell. I also had a burning sensation when I went to urinate," he recalls.
As a nurse, his mother knew something was amiss. Indeed, a doctor diagnosed nephritis, or inflammation of the kidneys.
His childhood was derailed. Regular visits to clinics and hospitals, where he was subjected to multiple tests and needle pokes, became a dreary routine. He had to give up ice cream, fizzy drinks and other treats children enjoy, and instead take a daily cocktail of steroids and other medication.
"Every day, I had to dip labsticks into my urine to test leakage of protein from my urine. And every month, I had to go for a blood test at the hospital," recalls Mr Tay, who developed a "moon face" and pot belly because of his condition.
Not long after, he had to undergo a biopsy at the hospital.
"They poked a long needle into my kidneys and took out a bit of flesh," he says.
Both he and his mother broke down when told that he had SLE (systemic lupus erythematosus): His immune system had gone rogue and was harming his kidneys instead of protecting it from disease.
Because he had to refrain from strenuous exercise, the former pupil of St Andrew's Primary was exempted from physical education classes.
"It really did my self-esteem in because I felt different from other children," he says, adding that he tried to hide his condition from his peers.
It did not help that he was taunted, even by teachers.
"When I was in Primary 4, I put on my PE attire because I wanted to try the long jump. The teacher told the class, 'Look, the sick man is coming.' "
He recalls another incident.
"I had to go to the toilet very often because the doctor told me to drink a lot of water. Another teacher ticked me off in front of the class: 'If not for your kidney problem, I would not allow you to go to the toilet.' It is something I still remember."
Except for a couple of worrying episodes, medication, for the most part, helped to stabilise his condition in his teens.
As he could not expend energy in rough-and-tumble play, he focused on his studies. He wanted to be a doctor just like Professor A. Vathsala, who has treated him since he was 14. Prof Vathsala is now co-director of renal transplantation at National University Centre for Organ Transplantation, National University Hospital.
Life began unravelling after he completed his national service.
He failed to get into medical school, and had to settle for pharmacy at the National University of Singapore.
"I was disappointed. I wanted to go overseas to study medicine. But my parents said no, probably because of my condition."
His three-year relationship with his girlfriend ended.
Frustrated and confused, he took on more modules and activities than he could handle and crashed spectacularly.
He remembers having to draw a kidney for an exam.
"I blanked out, I saw stars. My body seemed detached from my mind. I was very down, I realised that my mind could not process things anymore. I completed only half the paper," he says, adding that the episode took place on Sept 11, 2001, the day of the terrorist attacks on New York's World Trade Center.
His doctor told him that his kidneys were going to fail in six months. Worried for his mental state, she also sent him to a psychologist, who told him he was clinically depressed and advised him to take a break.
His son's failing memory prompted his father to send Mr Tay for an MRI brain scan.
The neurosurgeon who attended to him was Dr Balaji Sadasivan, the late senior minister of state for foreign affairs.
"He told me that the structure of my brain looked like that of a 50-year-old and that it would be difficult for me to complete my university studies as it was too stressful. He also told me to take a break," he recalls.
Mr Tay spiralled into a deep funk and became suicidal. But friends and family rallied around him and on their advice, he decided to take a break from his studies.
"I rested for six months. Every day, I walked to MacRitchie Reservoir, where I did qigong with the uncles and picked up meditation. I didn't think of anything," he says, adding that he started writing a journal.
It was a turning point in his life.
After a year's break, he decided to give up pharmacy and opt for a business degree at the Nanyang Technological University (NTU).
The decision was prompted by the realisation that his medical woes made him ill-suited for the rat race. He reckoned starting a business and being self-employed was the way to go.
In his second year, he and a friend set up a company, Second Home, to rent electrical appliances such as refrigerators and DVD players to undergraduates living in hostels.
Although it did not make money, the company broke even.
Unfortunately, he had another scare in 2013 when he developed a blockage in his ear.
A trip to an ear, nose and throat specialist revealed a tumour in his nose.
After a biopsy, an oncologist told him that the tumour was unlike anything he had seen before and it was hard to tell if it was malignant or benign. He recommended it be removed, a procedure which involved cutting up Mr Tay's nose and removing part of his skull.
In the worst-case scenario, he was told, half his face would be paralysed; in the best, he would have a big scar on his face.
Fortunately, his renal doctor stepped in and said the tumour could be the result of long-term medication for his renal condition.
He was given two choices: stop medication to see if the tumour would subside but risk kidney failure, or continue medication and run the risk of cancer.
"I chose the lesser of the two evils; I risked kidney failure."
There were side effects to stopping medication. Among other things, his body twitched and he suffered spasms in his legs which kept him up at night.
In eight months, his kidney failed and he had to start dialysis.
Among other things, he had to have operations to create a fistula - the connection of an artery to a vein to enable dialysis - on his left arm. "It's here," he says, allowing me to feel the big bump on his arm.
The toxin levels in his blood were off the charts by the time he had his first dialysis session.
"The whole fistula exploded because of the blood pressure," he says, wincing at the painful memory.
Dialysis, he says, was an expensive affair. Fortunately, a friend recommended him to the National Kidney Foundation (NKF), which made him a subsidised patient after several interviews.
Dialysis is not something he would wish on anybody. He had, he says, a "yellowish green" pallor, and was allowed to drink only 500ml of water a day.
His experience propelled Mr Tay to become a patient advocate for the NKF.
"I was young and could articulate their cause."
Although the dialysis sessions left him drained and tired, he managed to graduate with an honours degree in business and finance from NTU.
Upon graduation, he became an independent financial adviser as it allowed him to work at his own time and pace.
Building up a clientele while managing his health was not easy in the first couple of years.
"It got better after that. A lot of my clients trusted me because of my story," he says.
Unfortunately, his heart grew increasingly weak because of the fluid build-up in his body. In 2008, he was told he had only five years to live if he did not have a transplant.
"Actually, my mother wanted to donate her kidney when I went on dialysis. I told her to hold on because I had heard horror stories of transplantation. But when it became urgent, she had developed diabetes. My dad was too old," he says.
Moved by his suffering, his brother Caleb, younger by six years, volunteered to donate a kidney.
It took eight months to prepare Mr Tay for the operation.
"My body was in such a mess. I weighed only 44kg then," he says.
Three days before the operation, the surgeon told him there was a 50 per cent chance that he might not make it.
"But my renal doctor said, 'If you don't go, 100 per cent you will die.' "
The successful operation took five hours.
"The first thing that I did was to drink a litre of water. It felt so good," he says with a laugh.
By this time, he had started dating a renal nurse he met at NKF while undergoing treatment.
"Before the transplant, Sharon agreed to marry me if I survived the operation," he says.
One year after he got his new kidney, the couple got married. They tried for two years to start a family but were not successful.
A visit to the doctor in 2013 yielded bad news. "I did not just have low sperm count, I had zero sperm. I felt really down; it was another emotional hit."
Then he remembered that his renal doctor had advised him to freeze his sperm 12 years earlier because the medication he was taking might affect his fertility.
"She had the foresight," he says with a grin.
"So we defrosted my 12-year-old sperm and impregnated my wife through in-vitro fertilisation. One shot only we kena (hit); we had twins," he says with a grin, lapsing into Singlish.
Four months ago, the couple welcomed their third daughter.
Except for a couple of minor scares, life has been good since the transplant, says Mr Tay, who takes a daily cocktail of anti-rejection and other medications.
His family is his priority.
"I also make sure I have a support group of loved ones and friends because if anything happens to me, they will be the ones taking care of my family.
"I never forget I am living on grace."