A simple stool test could help GPs decide whether patients have irritable bowel syndrome (IBS) or other more serious bowel conditions.
Patients with lower bowel symptoms, such as chronic abdominal pain, diarrhoea or constipation are often seen in general practice.
Most of these patients have IBS, a condition that affects up to one in five people, and though troublesome, does not have serious effects in terms of damage to the bowel.
However, lower bowel symptoms could also suggest inflammatory bowel disease (IBD), which can have serious complications and includes conditions including ulcerative colitis and Crohn's disease. More than half of people with Crohn's disease need surgery within 10 years of diagnosis.
Since symptoms between IBD and IBS often overlap, making a correct diagnosis can be difficult. This can mean that patients with IBD could suffer delays with receiving treatment, or that those with IBS could receive unnecessary invasive treatment such as endoscopy.
New guidance from NICE on bowel symptom tests recommends simple stool tests which measure the levels of the protein calprotectin in stools, which can be traced in samples for several days.
If the bowel is inflamed, as in IBD, this can lead to higher than normal levels of the protein passing through the walls of the intestine.
Consequently, determining the quantities present can be used to help distinguish between inflammatory bowel diseases and non-inflammatory bowel diseases.
NICE says the tests are not recommended for people who are being considered for referral for suspected cancer, as inflammatory markers are also present in bowel cancer.
Professor Carole Longson, Director of the NICE Health Technology Evaluation Centre, said: "Currently a number of tests are carried out in both hospitals and GPs' surgeries to rule out conditions rather than to diagnose.
"This means people often face uncertainty, lots of visits to hospitals and their GP and repeated tests - some of them invasive and uncomfortable. Many people with IBD, particularly children with Crohn's disease, sometimes have to wait for several years for their condition to be diagnosed.
"Looking at the available evidence, we found that faecal calprotectin testing is a good way to distinguish between IBD and IBS."
She added: "As well as being of benefit to patients, the tests will also save the NHS money. They will reduce both the time spent searching for a diagnosis and the numbers of invasive procedures such as colonoscopy.
"The test is also likely to reduce the demands on colonoscopy departments which will be able to focus on people being investigated for more serious conditions such as bowel cancer."