A devastated daughter is demanding answers from the NHS after her mother died from multiple organ failure six days after being admitted to hospital with stomach pains.

Kamla Thakrar, 74, went to the accident and emergency department at St Helier Hospital in Sutton with stomach pains on December 19.

She was diagnosed with constipation and sent on her way without a CT scan or ultrasound.

Thirty-six hours later she was rushed to St George's Hospital in Tooting with severe abdominal pain and shortness of breath.

And six days after that her relatives were told they had just a few minutes to say goodbye to her before she died from multiple organ failure.

Now her grieving daughter, Joshna Thakrar, of Merton Park, wants the hospital to carry out a serious untoward investigation into her mother's death - which she believes was caused by a delay in diagnosis, doctors being pressured to operate and staff shortages.

She said: "When tragedy occurs, it presents a choice. You can give in to the void, the emptiness that fills your heart, your lungs and constricts your ability to think or even breathe.

"These past five months I have spent many of my moments lost in this void. And I know that many future moments will be consumed by this vast emptiness for me as well for my whole family."

Responding to her 21-page formal complaint last week - four months after the complaint was received and after missing four of its own deadlines - St George's Healthcare NHS Trust admitted a series of care failures including:

- Due to staff shortages, Miss Thakrar had to wheel her mother to and from X-ray and CT Scan and help her get in and out of bed.

The trust said: "At times of high demand within the department, there have been delays in the transportation of patients to diagnostics. This has been discussed with the general manager for facilities so that additional resources can be directed to the ED to reduce these delays."

- She had to wait in A&E for more than 13 hours before receiving a CT scan and had a gallstones problem diagnosed.

The trust said: "The hospital was facing considerable pressure at the time of your mother's attendance. This resulted in a number of patients remaining in the department longer than the four hour standard which we aim for."

- A nurse allegedly shouted at patients including Mrs Thakrar, saying "I am busy and will attend to you when I can."

The trust said: "Matron Russell has spoken to all of the staff on Richmond Ward and discussed the importance of appropriate communication and how their actions can have a negative impact on patients and their relatives."

- A patient was seen to fall out of bed after being ignored by nurses.

The Trust said: "Matron Russell is very sorry that this incident resulted in distress for your mother and your family. It is not acceptable for patients to be ignored and Matron Russell will be speaking to the nursing team involved to highlight your observations and understand why this occurred."

Kamla Thakrar at St George's Hospital in Tooting

But chief executive Miles Scott denied any serious wrongdoing. He wrote: "Mr Odutoye does not believe that there was anything wrong in how your mother's case was surgically and medically handled.

"Unfortunately, however, despite escalating levels of care and intervention, the medical and surgical teams were not able to improve your mother's condition quickly enough to prevent her death.

"All the teams involved in your mother's care are truly sorry about this."

Originally from India, the grandmother and mother-of-nine had family all over the world asking for regular updates on her condition.

The resulting rigorous documentation of her experience represents an unusually detailed insight into a patient's treatment at a stretched hospital which has a deficit of more than £10m and needs to find £43m in savings this year.

Miss Thakrar, who refused to leave her mother's side, initially to act as a translator but later due to concerns about the quality of care, was advised by one nurse to direct her complaints to Prime Minister David Cameron.

She said her mother's death was "a complete shock" to her whole family and she believed it could have been prevented by a faster diagnosis.

She said the risks of surgery were not clear and she believed doctors were pressurised into carrying out a second laparotomy (a major abdominal exploratory operation) because the head of intensive care refused to accept her mother into his unit.

A blood scan and electrocardiogram show her mother suffered a heart muscle injury before her death, which was only confirmed by the hospital last week.

If the family had been aware of this at the time, Miss Thakrar said they wouldn't have agreed to the final surgery before her mother could express her final wishes.

The trust declined to comment on whether pressures on staff and resources may have contributed to Mrs Thakrar's poor experience in hospital, and ultimate death.

Last month Daniel Elkeles, chief executive of Epsom and St Helier University Hospital NHS Trust, responded to her complaint about being discharged from St Helier Hospital.

He said doctors were "almost certain" her mother had gallstones for months prior to her death and there was evidence of constipation from x-rays which can cause abdominal pain.

But he said clinical findings and blood tests did not show evidence of gallbladder infection or perforation - which would have prompted further investigations - adding "it is likely that this complication developed very rapidly after her presentation at St Helier Hospital."