Skip to main content

Health condition

Peutz-Jeghers syndrome, inherited polyps, lifelong surveillance - and a clear plan.

A rare inherited condition of the STK11 gene, marked by freckle-like spots and bowel polyps. With regular scopes, scans and expert care, most complications can be prevented or caught early.

Jump to treatment
A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against BSG, ACPGBI and UKCGG polyposis guidance and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK practice including STK11 testing, capsule endoscopy and double-balloon enteroscopy.

Key facts

Peutz-Jeghers syndrome at a glance.

The essentials, in plain English - what causes it, where polyps grow, and how it is followed up in the UK today.

  • What it is

    A rare inherited condition in which hamartomatous polyps grow in the digestive tract, alongside dark freckle-like marks on the lips and skin.

  • Cause

    A change (variant) in the STK11 gene, also called LKB1. It is autosomal dominant, so each child of an affected parent has a 1 in 2 chance of inheriting it.

  • Where polyps grow

    Most often in the small bowel, but also the stomach and colon. Polyps are not cancerous themselves but can bleed, block the bowel or cause intussusception.

  • Cancer risk

    Lifetime risk is markedly raised across the bowel, pancreas, breast, ovary, cervix and testis, which is why lifelong surveillance matters.

  • Surveillance

    Endoscopy and small bowel imaging usually start in childhood or adolescence and repeat every one to three years, with organ-specific screening added in adulthood.

  • Family history

    Around half of people have a relative with the condition. The rest have a new (de novo) variant, so no family history does not exclude the diagnosis.

Why this guide matters

Prevention is the whole point.

Peutz-Jeghers syndrome is rare, so it is often recognised late. The three points below shape everything else on this page.

  • The freckles are a clue worth acting on

    Dark spots on the lips and inside the mouth in a child are easy to dismiss. Recognising them early can lead to a diagnosis before an emergency.

  • Polyps are managed before they obstruct

    Removing larger small bowel polyps on a planned basis is far safer than emergency surgery for intussusception.

  • Screening reaches beyond the bowel

    Breast, pancreas, gynaecological and testicular checks form part of a lifelong plan agreed with a specialist team.

How the diagnosis is made

From a first clue to a lifelong plan.

The steps a UK GP, geneticist or gastroenterologist will normally follow, in order - so you know what to expect and why.

  1. 01

    Assessing

    History and family tree

    Your clinician asks about freckling, abdominal pain, bleeding, past bowel surgery and cancers in relatives on both sides of the family.

  2. 02

    Assessing

    Skin and mouth examination

    Dark macules on the lips, around the mouth, inside the cheeks and on the fingers and toes are one of the clearest clues.

  3. 03

    Assessing

    Blood tests

    A full blood count and ferritin look for iron deficiency anaemia from slow, hidden bleeding from polyps.

  4. 04

    Confirming

    STK11 genetic testing

    Usually arranged through a clinical genetics service after counselling. A pathogenic variant confirms the diagnosis in most people.

  5. 05

    Confirming

    Baseline endoscopy

    Gastroscopy and colonoscopy map polyps in the stomach and large bowel and allow removal of larger ones at the same visit.

  6. 06

    Planning

    Small bowel imaging

    Capsule endoscopy or MR enterography views the small bowel, where the polyps that cause intussusception tend to sit.

  7. 07

    Planning

    Specialist multidisciplinary plan

    Genetics, gastroenterology and, where relevant, breast, gynaecology and urology agree a personal surveillance schedule.

Typical timeline: genetic results in a few weeks, with baseline scopes and imaging following over the next few months.

Symptoms

What Peutz-Jeghers syndrome looks and feels like.

Skin signs often appear first, digestive symptoms follow. Some people have very few, and screening finds polyps before symptoms begin.

  • Lip and perioral macules

    Flat blue-grey to brown spots on and around the lips, often noticed in infancy or early childhood.

  • Buccal and digit pigmentation

    Spots inside the cheeks, and on the fingers, toes, hands and feet. Skin marks can fade after puberty but oral ones usually persist.

  • Colicky abdominal pain

    Cramping pain that comes and goes, often from a polyp temporarily telescoping or partly blocking the bowel.

  • Vomiting and bloating

    Repeated vomiting, a swollen tummy or difficulty passing wind and stool can signal bowel obstruction.

  • Rectal bleeding or black stools

    Visible blood, or dark tarry stools, from polyps in the stomach, small bowel or colon.

  • Fatigue and pallor

    Slow, unnoticed blood loss leads to iron deficiency anaemia: tiredness, breathlessness, pale skin and poor concentration.

  • Hormonal and gynaecological signs

    Breast enlargement in boys, early puberty, irregular vaginal bleeding or a testicular lump can point to related tumours.

  • Red flag - severe pain with vomiting

    Sudden, severe abdominal pain with vomiting suggests intussusception or obstruction and needs emergency assessment.

Treatment

How Peutz-Jeghers syndrome is managed in the UK.

There is no cure for the underlying gene change. Care centres on surveillance, removing polyps early, screening for cancer and supporting the whole family.

  • Surveillance programme

    Scheduled upper and lower endoscopy plus small bowel imaging, usually every one to three years, tailored to polyp burden and age.

  • Endoscopic polypectomy

    Polyps in the stomach and colon are removed through the endoscope, most often when they are larger than about 1 cm.

  • Double-balloon enteroscopy

    A long, flexible scope reaches deep into the small bowel to remove large polyps before they cause intussusception.

  • Surgery for complications

    Laparotomy or laparoscopy may be needed for intussusception, obstruction or bleeding, with a bowel-sparing approach wherever possible.

  • Iron and anaemia treatment

    Oral or intravenous iron corrects anaemia while the source of bleeding is dealt with by polyp removal.

  • Breast and gynaecological screening

    Regular breast imaging, usually with MRI, and gynaecological review begin in adulthood and are agreed with a specialist team.

  • Pancreatic and testicular checks

    Pancreatic surveillance with MRI or endoscopic ultrasound may be offered, and boys have testicular examination during routine reviews.

  • Genetic counselling

    Explains inheritance, supports family cascade testing and helps with reproductive choices, alongside psychological support.

What this guide is based on

The sources behind every claim on this page.

UK national guidance and specialist society standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your GP, geneticist or gastroenterologist knows your history and can tell you which parts apply to you. If in doubt, get seen.

  • BSG, ACPGBI and UKCGG. Guidelines for the management of hereditary colorectal cancer and polyposis syndromes (Monahan et al., Gut, 2020).

  • NHS England Genomic Medicine Service. National Genomic Test Directory: inherited polyposis and cancer predisposition.

  • European Society of Gastrointestinal Endoscopy (ESGE). Endoscopic management of polyposis syndromes.

  • GeneReviews and Orphanet. Peutz-Jeghers syndrome: clinical summary and STK11 variants.

Red flags

When to seek urgent help.

Most of the time the condition is followed up in planned clinics. These are the situations that cannot wait for the next appointment.

  • Sudden severe abdominal pain

    Especially with vomiting or a distended tummy. This may be intussusception or obstruction and needs emergency assessment, as bowel can lose its blood supply.

  • Persistent vomiting

    Green (bile-stained) vomit, or vomiting that will not settle, suggests the bowel is blocked. Go to A&E.

  • Black tarry stools or heavy bleeding

    Fresh blood, black stools, fainting or a racing heart after bleeding need urgent same-day medical review.

  • Symptoms of anaemia

    Marked tiredness, breathlessness or pallor deserve blood tests promptly, even if there is no visible bleeding.

  • A new breast lump

    Any lump, nipple change or skin change should be assessed urgently, as breast cancer risk is raised from early adulthood.

  • Persistent upper abdominal or back pain

    With weight loss or jaundice this may be a pancreatic problem and needs a prompt specialist review.

  • Abnormal vaginal bleeding

    Bleeding between periods, after sex or after the menopause should be checked, given the raised gynaecological cancer risk.

  • Testicular lump or breast growth in a boy

    A testicular swelling, or breast tissue developing in a boy, may reflect a hormone-producing tumour and needs review.

  • Missed or delayed surveillance

    If your check-ups have lapsed, contact your genetics or gastroenterology team and ask to be rebooked rather than waiting for symptoms.

Living with it

A lifelong condition, with a clear safety net.

Four things that make the biggest difference - keeping surveillance dates, sharing the result with family, looking after your mind and knowing what to do when pain strikes.

A quiet reminder

Regular checks are how surprises are avoided.

Most people with the syndrome who stay in surveillance are able to work, travel and raise families. The routine is a form of reassurance.

  1. 01 Routine

    Keep every surveillance date

    Regular scopes and scans catch polyps while they are small enough to remove endoscopically, which is the best protection against emergency surgery.

  2. 02 Family

    Share the result with relatives

    Parents, siblings and children can be offered testing. Genetics services can write a letter you can pass on if that feels easier.

  3. 03 Wellbeing

    Look after your mental health

    Living with lifelong screening and cancer risk is a heavy load. Psychological support and peer groups help, so ask your team about them.

  4. 04 Be prepared

    Know your plan for sudden pain

    Carry a summary of your diagnosis and tell any A&E team you have Peutz-Jeghers syndrome, as sudden pain needs a different approach.

Frequently asked

Everything we get asked about Peutz-Jeghers syndrome.

Quick answers on inheritance, polyps, surveillance and testing family members.

  • What is Peutz-Jeghers syndrome?

    It is a rare inherited condition caused by a variant in the STK11 gene. It leads to hamartomatous polyps in the digestive tract, dark freckle-like marks around the mouth and on the hands and feet, and a raised lifetime risk of several cancers.

  • How is it inherited?

    It is autosomal dominant, so a parent with the variant has a 1 in 2 chance of passing it to each child. Some people are the first in their family because the variant arose newly, so a clear family history is not needed for the diagnosis.

  • Are the polyps cancerous?

    Hamartomatous polyps are not cancer, but they can cause bleeding, blockage and intussusception, and people with the syndrome carry a higher risk of developing cancers in the bowel and other organs over a lifetime. Surveillance is designed to spot problems early.

  • How often will I need scopes and scans?

    Most guidance suggests starting in childhood or adolescence and repeating small bowel and endoscopic checks every one to three years, depending on how many polyps are found. Your team will set a schedule that fits your own findings.

  • Can polyps be removed without surgery?

    Often yes. Polyps in the stomach and colon can be removed through a standard endoscope, and double-balloon enteroscopy can reach many in the small bowel. Surgery is kept for complications or polyps that cannot be reached.

  • Should my relatives be tested?

    Once a pathogenic STK11 variant is found in you, close relatives can have a simple targeted test. Those who carry it join surveillance, and those who do not can usually be reassured and discharged from screening.

Related content

Keep reading.