Stool analysis comprises a series of tests done on stool samples, mostly to diagnose any existing digestive tract conditions. Few of these conditions involve infections from bacteria, viruses, and parasites, insufficient nutrient absorption, or cancer. The most common condition, however, is an infection caused by pathogenic bacteria.

The digestive tract comprises both pathogenic bacteria and normal bacteria that are part of the flora. The bacteria found through stool analysis help determine the bacteria present in the digestive tract of an individual. They are known to play an essential role in the digestion of food and the prevention of the growth of pathogenic bacteria.

Pathogenic bacteria can enter the digestive tract when the balance of the normal flora is affected by the use of broad-spectrum antibiotics. These antibiotics prevent the growth of normal flora and allow pathogenic bacteria to invade the digestive tract. Pathogenic bacteria can also enter the digestive tract if someone eats or drinks contaminated food or water.

The common symptom of pathogenic bacteria infection is diarrhoea, associated with abdominal pain, cramps, mucous in stool, nausea, and dehydration. Dehydration can further lead to an electrolyte imbalance, which can cause fatigue and light-headedness.

Diarrhoea is known to be the third leading cause of death in children in India. It is responsible for the death of approximately 13% of children aged below five years. Efforts are being made to reduce the number of cases and deaths due to diarrhoea in India.

Other Names of Stool Analysis

• Stool sample test
• Faecal sample test
• Stool routine and microscopy
• Routine stool examination

What does the test detect and who is it prescribed for?

The stool analysis is used for the diagnosis of digestive tract infections that may be caused by pathogenic bacteria or parasitic and viral infections.

The stool analysis is prescribed by the doctor for individuals who have the following symptoms:

• Prolonged diarrhoea
• Stool with mucous or blood
• Nausea
• Stomach pain along with occasional cramps
• Fever

There is increased concern in the following cases:

• Old age
• Weakened immune system
• Severe symptoms
• Acute dehydration
• Consumption of contaminated food or water

The doctors may prescribe antibiotics to get rid of the infection and ORS to help with the dehydration.

The stool analysis requires a fresh stool sample that is collected in a container with a lid and labelled. The sample must be transported to the laboratory within two hours of collection.

Test Preparation

Stool analysis does not require any special preparation either before or after the test. Samples can be collected during any time of the day, although sample collection is preferred in the morning.

What parameters are included?

The stool analysis process involves the collection of stool samples that are then sent to a laboratory. At the laboratory, it undergoes microscopic examination, chemical tests as well as microbiological tests. The stool is checked for odour, colour, consistency, and presence of mucous. The stool is also tested for the presence of blood, white blood cells and sugars. Additionally, the pH of the stool is also measured.

Dehydration, Electrolyte disbalance, Severe diarrhoea

The stool analysis results are available 1 to 3 days after sample collection, although a longer time is taken for the detection of parasites. The result can either be positive or negative. There is no set range for stool analysis results.

A positive result indicates the presence of a few of the common pathogens, such as Salmonella, Shigella, and Campylobacter, while a negative result indicates the absence of these bacteria.

The results of stool analysis can also be categorised as normal and abnormal based on the physical characteristics of the stool. The stool is considered normal if there is no presence of mucus, blood, pus or harmful pathogens. It is also considered to be normal when it is brown, well-formed, soft, and is shaped like a tube. The stool is considered to be normal when it is green, yellow, black, or red in colour, along with abrupt consistency. Also, the presence of blood, pus, and mucus makes the stool abnormal.

The stool analysis involves a wide range of tests that determine the physical characteristics of the collected stool samples and their chemical composition. It helps to detect the presence of any digestive tract infections, especially bacterial.

A positive result indicates the presence of an infection and causative organisms responsible for the infection. A negative result indicates the absence of these pathogenic organisms. Early detection and treatment of diarrhoea are important as they can lead to dehydration that further causes electrolyte disbalance. Stool analysis thus serves an important role in the early detection and treatment of diarrhoea.