Preparing for stool culture

Overview

A stool culture is a lab test that looks for harmful bacteria in a sample of your stool (poop). It helps find the cause of diarrhea or other digestive symptoms.

Yes, stool cultures are a common test when someone has diarrhea that lasts more than a few days, especially if there is blood, mucus, or fever.

Anyone can be asked to provide a stool culture, but it is more often done in children, older adults, people with weakened immune systems, or those who have recently traveled to areas with poor sanitation.

Symptoms

Common symptoms

• Watery or loose diarrhea lasting more than 2 days
• Blood or mucus in your stool
• Stomach cramps and pain
• Nausea and vomiting
• Fever (temperature above 100.4°F or 38°C)

Symptoms in children

• Persistent diarrhea (more than 24 hours) with or without vomiting
• Signs of dehydration: dry mouth, no tears when crying, fewer wet diapers
• Fussiness or unusual drowsiness
• Bloody or very watery stool

Symptoms in older adults

• Diarrhea that lasts more than a day with weakness or confusion
• Signs of dehydration: dry mouth, decreased urination, lightheadedness
• High fever (over 101°F or 38.3°C)
• Bloody stool or severe abdominal pain

Causes

Main causes

• Infection with bacteria such as Salmonella, Campylobacter, Shigella, or E. coli from contaminated food or water
• Infection with other germs like parasites (sometimes ordered as a separate test)
• Recent travel to areas where food and water safety may be poor
• Direct contact with infected animals or people

Risk factors

• Traveling to developing countries
• Eating raw or undercooked meat, eggs, or unpasteurized milk
• Drinking untreated water
• Living or working in crowded settings (like daycares, nursing homes)
• Having a weakened immune system (from illness or medications)

When to see a doctor

See a doctor urgently if:

• Your diarrhea is very frequent (more than 6 episodes in 24 hours) and you cannot keep fluids down
• You see blood or mucus in your stool
• You have a fever above 101°F (38.3°C) that lasts more than a day
• You have severe stomach pain or vomiting that prevents you from eating or drinking

Book a routine appointment if:

• You have mild diarrhea that does not get better after 3 days
• You suspect you may have eaten something contaminated (for example, at a picnic or from a restaurant)
• You have been around someone with a confirmed bacterial infection

Diagnosis

A stool culture is the main test to diagnose a bacterial gut infection. Your doctor will give you a clean container and instructions for collecting a stool sample. The sample is sent to a lab, where technicians try to grow bacteria over several days. If harmful bacteria grow, the lab can identify them and sometimes test which antibiotics might kill them.

Tests that may be done

• Stool culture (the main test)
• Sometimes a test for parasites or viruses if bacteria are not found
• Rarely, a blood test or a sample from the colon (colonoscopy) if symptoms are severe or long-lasting

What to expect at your appointment

You will receive a kit (usually a small plastic container and a collection hat or plastic wrap). Collect a small amount of stool, trying not to mix it with urine or toilet water. Place the sample in the container, seal it, and return it to your doctor's office or lab within a few hours or refrigerate it as instructed. The process is simple and painless.

Treatment

Treatment depends on what the stool culture finds. Many bacterial infections go away on their own with rest and fluids. If a specific bacterium is found, your doctor may recommend antibiotics. It is important not to stop anti-diarrhea medicines (like loperamide) unless your doctor tells you, because sometimes they can make the infection last longer.

Self-care at home

• Drink plenty of clear fluids (water, clear broths, oral rehydration drinks) to prevent dehydration
• Avoid dairy, caffeine, alcohol, and high-fiber or spicy foods until the diarrhea stops
• Rest your digestive system with bland foods like rice, toast, bananas, and applesauce
• Wash your hands thoroughly after using the bathroom and before eating to prevent spreading germs

Medical treatments

If a bacterial infection is confirmed and your symptoms are severe or you are at high risk (very young, old, or immunocompromised), your doctor may prescribe an appropriate antibiotic. They will choose one based on the type of bacteria and its sensitivity. Never take leftover antibiotics or someone else's prescription.

When is surgery considered?

Surgery is almost never needed for infections that require a stool culture. Rarely, if a complication like a hole in the bowel or severe abscess occurs, surgery may be necessary, but that is extremely uncommon.

Living with this condition

While waiting for stool culture results and during recovery, focus on staying hydrated and getting rest. Plan to stay close to a bathroom. Activities that require being away from home may be difficult until symptoms improve.

Lifestyle tips

• Drink small amounts of fluid often rather than large amounts at once
• Keep a simple diet and reintroduce foods slowly as you feel better
• Avoid preparing food for others until you have no symptoms for at least 48 hours

Diet and exercise

Stick to a bland, low-fibre diet until diarrhea stops. After recovery, gradually return to your normal diet. Light activity like walking is fine if you have energy, but avoid intense exercise until you are fully hydrated and feeling well.

Mental health and emotional wellbeing

Having ongoing diarrhea can be stressful, embarrassing, and isolating. It may interfere with work, school, and social life. It is normal to feel frustrated or worried. Talk to your doctor if the anxiety becomes hard to manage.

Prevention

Many bacterial gut infections can be prevented with good hygiene and safe food and water practices. Wash hands before eating and after using the bathroom. Cook meat and eggs thoroughly. Avoid unpasteurized dairy. When traveling, drink bottled water and avoid raw fruits and vegetables that may have been washed in tap water.

Vaccines

There are vaccines for some causes of diarrhea (like rotavirus and typhoid), but these are not routinely given for the bacteria commonly found in stool cultures. Ask your travel health clinic about recommended vaccines before going abroad.

Screening programmes

No routine screening is done for stool bacteria. People with persistent or severe symptoms are tested based on their doctor's decision.

Complications

If left untreated

• Severe dehydration that may require hospital IV fluids
• Electrolyte imbalances (loss of salts your body needs)
• Spread of the infection to others in your household
• Rarely, the infection can spread from your gut to the bloodstream (sepsis)

Long-term outlook

Most bacterial gut infections resolve on their own within a week. With proper fluids and rest, you will likely feel better in a few days. If the cause is found and treated, the outlook is very good. Even in severe cases, hospitals can provide fluids and antibiotics to help you recover fully. Serious complications are rare, and most people make a complete recovery.

Find support

External links open third-party websites. Ruqelo Health is not responsible for external content. Listing an organisation does not imply endorsement.