C. difficile (C. diff): symptoms, treatment and how long it lasts

The NHS says your symptoms should improve a few days after starting the new course of antibiotics, but it may be 1 to 2 weeks before the infection clears up completely. NHS inform gives a similar picture: most people recover from a C. difficile infection within one to two weeks after treatment begins.

NICE adds a practical point for clinicians. Diarrhoea may take 1 to 2 weeks to resolve, so it is not usually possible to judge whether an antibiotic is ineffective until about day 7.

Symptoms can return. NHS inform says they come back in around 1 in 5 cases, and treatment may need to be repeated. The NHS advises going back to the GP if symptoms get worse, if you feel very unwell after starting the antibiotics, or if symptoms come back afterwards.

C. diff bacteria usually live harmlessly in the bowel alongside many other types of bacteria. NHS inform says they are found in the digestive system of about 1 in every 30 healthy adults, and the other bowel bacteria normally keep them under control.

The problem starts when that balance changes. The NHS says that when you take antibiotics, the balance of bacteria in your bowel can change and cause an infection. NHS inform explains that the C. diff bacteria then multiply and produce toxins that make the person ill.

Not everyone who takes antibiotics gets C. diff, and diarrhoea is a common side effect of antibiotics in general. NHS inform notes that having diarrhoea while taking antibiotics does not necessarily mean you have a C. difficile infection; a stool sample is used to confirm it.

The NHS says you are more likely to get a C. diff infection if any of the following apply. NHS inform adds a few more groups.

• You are over 65.

• You are taking, or have recently taken, antibiotics. NHS inform highlights broad-spectrum antibiotics, several different antibiotics at the same time, or long-term antibiotics.

• You are staying in hospital or a care home for a long time.

• You have a weakened immune system, for example from diabetes, kidney failure or chemotherapy.

• You take a proton pump inhibitor (PPI) such as omeprazole, or other medicines that reduce stomach acid.

• You have had a C. diff infection before.

• NHS inform also lists inflammatory bowel disease, cancer, kidney disease, steroid treatment and surgery on the digestive system.

NHS inform says symptoms usually develop while you are taking antibiotics, or within the last few weeks after finishing them. The NHS lists the common symptoms as diarrhoea, a high temperature, loss of appetite, feeling sick and a stomach ache.

NHS inform gives more detail: watery diarrhoea, which can be bloody; painful tummy cramps; feeling sick; signs of dehydration such as a dry mouth, headaches and peeing less than usual; a temperature above 38C; and loss of appetite and weight loss.

Serious complications can develop. NHS inform describes damage to the bowel or severe dehydration, which may cause drowsiness, confusion, a rapid heart rate and fainting.

Yes. The NHS says C. diff can spread to other people very easily if bacteria from the poo of someone with the infection get onto objects and surfaces. NHS inform explains that outside the body the bacteria turn into resistant cells called spores, which can survive for long periods on hands, surfaces such as toilets, objects and clothing unless thoroughly cleaned, and can infect someone else if they get into the mouth.

Someone with the infection is generally considered infectious until at least 48 hours after symptoms have cleared, according to NHS inform.

• Stay at home until at least 48 hours after your diarrhoea stops.

• Wash your hands regularly with soap and water. Alcohol hand gel does not kill or remove C. diff.

• Clean the toilet and surrounding area after each use. NHS inform recommends a bleach-based cleaner on the toilet, flush handle, light switches and door handles.

• Wash clothes and sheets that have poo on them separately, at the highest possible temperature.

• Do not share towels and flannels.

• When visiting someone in hospital, follow visiting guidance, wash hands with liquid soap and water, and avoid visiting if you have recently had diarrhoea.

If a doctor thinks you have C. diff, they may ask for a poo sample to be tested. The NHS says it can sometimes be treated at home, or you might need hospital care, because infections can lead to more serious problems such as sepsis.

The NHS lists two main steps: stopping any antibiotics you are already taking, if possible, and taking a new 10-day course of another antibiotic that can treat C. diff. NHS inform gives a range of 10 to 14 days, and notes that in mild cases stopping the antibiotic that triggered the infection may be the only treatment needed.

NICE guideline NG199 sets out the choice for adults. Vancomycin by mouth is first-line for a first episode; fidaxomicin is second-line if vancomycin is ineffective. A further episode within 12 weeks of symptoms settling (a relapse) is treated with fidaxomicin. Life-threatening infection needs urgent specialist advice, which may include surgery. NICE also says to review other medicines, such as proton pump inhibitors and laxatives, and to manage fluid loss as for acute gastroenteritis.

NICE advises against antimotility medicines such as loperamide, and the NHS agrees: do not take medicine to stop diarrhoea, because it can prevent the infection being cleared. Finish every antibiotic, even if you feel better.

NICE describes a further episode within 12 weeks of symptoms resolving as a relapse and one after more than 12 weeks as a recurrence. The NHS says that if the infection comes back 2 or more times, you may be offered a faecal microbiota transplant, in which bacteria from a healthy person's poo are put into your gut to help stop the infection. NICE likewise says to consider this treatment for adults who have had 2 or more previous episodes.

NICE does not recommend antibiotics or probiotics to prevent C. diff, and recommends that a diagnosis is recorded when someone moves between care settings, so it is taken into account before any future antibiotics are prescribed.

NICE says that for children and young people under 18, an oral antibiotic is offered to treat suspected or confirmed C. diff, and treatment should be started by, or after advice from, a microbiologist, paediatric infectious diseases specialist or paediatric gastroenterologist. The choice of antibiotic is based on what is recommended for adults, taking account of licensing and availability.

The sources used for this page do not give pregnancy-specific advice about C. diff. NICE says to check the BNF for appropriate use and dosing of the antibiotics in specific groups, including pregnancy and breastfeeding. If you are pregnant and have diarrhoea after antibiotics, speak to your GP or midwife promptly; do not take anti-diarrhoea medicine.

If you are well enough to be treated at home, NHS inform suggests the following. Your GP may contact you regularly to check you are getting better.

• Finish the whole course of antibiotics you are prescribed, even if you feel better.

• Drink plenty of fluids to avoid dehydration, and eat plain foods such as soup, rice, pasta and bread if you feel hungry.

• Take paracetamol for tummy pain or a fever.

• Do not take anti-diarrhoeal medicine.

• Phone your GP if symptoms return after treatment finishes, as treatment may need to be repeated.

The NHS says to ask for an urgent GP appointment or get help from NHS 111 if you have diarrhoea and you are taking or have recently taken antibiotics, you have bloody diarrhoea or bleeding from the bottom, or you have diarrhoea for more than 7 days.

NHS inform says to contact your GP practice for severe diarrhoea, severe tummy pain, a high fever, a rapid heart rate, fainting, or signs of severe dehydration such as confusion, drowsiness or passing very little urine or none. It suggests phoning rather than visiting the surgery, because attending with a possible C. diff infection can put others at risk. If your GP is closed, phone 111.

C. diff is usually diagnosed through a stool test requested by a GP or hospital team. Treatment is often managed by the GP at home, with hospital care for people who are severely unwell, at high risk or not improving. Recurrent infections are usually looked after by specialist teams.

Private doctors can arrange stool testing and prescribe treatment, but the same safety advice applies: tell any clinician you have seen about recent antibiotics, and ask that a diagnosis of C. diff is recorded in your notes.