A woman thought she was suffering from Crohn's disease for six years, until surgery revealed the real source of her symptoms were the remnants of a sachet of Heinz sauce.

The 41-year-old patient had endured bouts of acute stomach pain and bloating lasting up to three days, prompting doctors in England to diagnose her with the serious bowel condition.

But when she failed to respond to standard treatment, and began to display "severe" symptoms of the disease, keyhole surgery was deemed the only option.

The procedure found an inflamed mass piercing the wall of her small intestine, which turned out to be two pieces of plastic packaging bearing Heinz branding.

The woman insisted she had no memory of tucking into a meal involving the sachet, according to the report in the British Medical Journal.

Once removed, her symptoms were cured almost instantly and she remained clear in all of her follow-up appointments up to five months afterwards - with no remaining sign that she could have Crohn's disease.

Doctors said it was the first case of ingested plastic packaging mimicking the symptom of Crohn's disease.

Previous reported instances involved swallowed toothpicks.

Most cases result in the foreign items being passed through naturally, with between 10% and 20% requiring an endoscopy and just 1% needing surgery.

The report concluded: "It is important to consider alternative surgical diagnoses in patients with presumed Crohn's disease unresponsive to standard treatment."