Rectal bleeding

Rectal bleeding can appear as bright red blood on the toilet paper or in the bowl, or as dark red or black stools. It may come with pain, a change in bowel habit, tiredness or unexplained weight loss. Even if the bleeding is light or stops on its own, it is worth having it checked so the cause can be found.

  • Specialist colonoscopist at St Mark’s National Bowel Hospital.
  • PhD in colonoscopy.
  • 4,500+ procedures.

Consultations usually available within 1 to 2 weeks, including evenings and weekends, in person or remotely.

Call - 07435 081678
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Colonoscopy

A colonoscopy uses a thin, flexible camera to examine the whole lining of your large bowel. It can help find the cause of symptoms such as bleeding, abdominal pain, a change in bowel habit or anaemia. If polyps are found, Dr Ahmad can usually remove them during the same procedure and take biopsies if needed, to help avoid a second visit.

Specialist colonoscopist at St Mark’s National Bowel Hospital · PhD in
colonoscopy · 4,500+ procedures.

Consultations usually available within 1 to 2 weeks, including evenings
and weekends, in person or remotely.

Book a consultation
Call - 07435 081678
4.97 Out of 5
Rated on Doctify

22 verified patient reviews

Consultant at

Insurers accepted

  • Allianz
  • Aviva Health
  • AXA Health
  • Bupa
  • Healix
  • Vitality Health
  • WPA

We can help with pre-authorisation. Contact Dr Ahmad’s secretary on 07435 081678 or at clinic@drahmirahmad.com.

The symptoms

Rectal bleeding at a glance

The key facts about rectal bleeding, from the signs to look for to when to get it checked.

Signs

Bright red blood on the toilet paper or in the bowl, or dark red or black stools.

Other signs

Bleeding may come with pain, a change in bowel habit, tiredness or unexplained weight loss.

Causes

Haemorrhoids and small tears are common, but polyps, bowel inflammation and other conditions can also cause bleeding.

Get checked

Even if the bleeding is light or stops on its own, it is worth having it checked so the cause can be found.

Urgent

If you have heavy bleeding, dizziness, fainting or severe pain, call 999 or go to A&E.

Next step

A colonoscopy with Dr Ahmir Ahmad can examine the whole lining of your large bowel, find the cause and take biopsies if needed.

What rectal bleeding can mean

The symptoms

What rectal bleeding can mean

A clear look at the cause of your bleeding

Rectal bleeding is often caused by haemorrhoids or a small tear, but it can also come from polyps, inflammation of the bowel or other conditions. The blood may be bright red on the toilet paper or in the bowl, or dark red or black in the stool. Because the cause cannot be judged by looking at the blood alone, it is always worth having it checked.

Dr Ahmad will start by listening to your symptoms and medical history. If a closer look is needed, a colonoscopy uses a thin, flexible camera to examine the whole lining of your large bowel and find the source of the bleeding. If he finds a polyp, he can usually remove it during the same procedure and take small tissue samples (biopsies) for testing.

  • Bright red or dark blood, or black stools.
  • change in bowel habit, pain, tiredness or weight loss.
  • Bleeding that is light, or that stops and starts.
  • A colonoscopy to find the cause, with polyps removed when safe to do so.
Darker blood Brighter blood Stomach and upper gut Colon Rectum Anus and anal canal

Blood from low down tends to be bright red, and blood from higher up is darker. The colour is only a clue, so the cause still needs checking.

What does your bleeding look like?

    Heavy bleeding, dizziness, fainting or severe pain? Call 999 or go to A&E.

    Your appointment

    What happens on the day

    From your consultation to your results, here is how the cause of your bleeding is found and treated.

    Step 1: Before your visit

    Make a note of when the bleeding started, what it looks like, how often it happens and any other symptoms, such as pain or a change in bowel habit. Bring a list of the medicines you take, including blood thinners. Please don’t stop any medicine unless your doctor tells you to.

    Step 2: Your consultation

    Dr Ahmad will ask about your symptoms and medical history, and may examine you. He will explain the likely causes, answer your questions and recommend any tests you need. This can include blood tests to check for anaemia.o see you to discuss your sedation options.

    Step 3: Finding the cause

    Most people with rectal bleeding need a colonoscopy to see the whole lining of the large bowel and find where the bleeding is coming from. Dr Ahmad gently guides a thin, flexible camera around the bowel, and you may feel some pressure, bloating or cramping. Any polyps found are removed if it is safe to do so at the time, and biopsies are taken if needed.

    Step 4: Results and treatment

    Dr Ahmad will explain what he found, what is causing your rectal bleeding and what it means for you. If you have a colonoscopy, your report will be shared with your secure patient portal. If treatment or follow-up is needed, he will talk you through the options and arrange it with you.

    Why choose Dr Ahmad for your rectal bleeding assessment?

    Expert care, clear answers and support at every step.

    • Consultant-led care

      Dr Ahmad assesses your rectal bleeding himself. He is a consultant gastroenterologist with a PhD in colonoscopy, has published on the procedure and has carried out more than 4,500 procedures.

    • Treated in one visit

      If a colonoscopy is needed to find the cause of your bleeding, polyps are removed during the same procedure when it is safe to do so. Multiple or very large polyps may need a separate, planned therapeutic procedure.

    • Your comfort matters

      Dr Ahmad uses modern water-assisted insertion techniques to help improve comfort. You can also choose the level of sedation or pain relief that suits you, and the team will support you throughout.

    • Clear answers on the day

      If you have a colonoscopy, Dr Ahmad explains the findings before you go home, including what is causing your bleeding, and your report is shared with your secure patient portal. If samples are taken, he’ll review the results with you in clinic about two weeks later.

    Colonoscopy quality you can check

    Dr Ahmad’s results from the National Endoscopy Database, January 2025 to October 2026 (421 procedures).

    • Caecal intubation rate

      96%

      How often the camera reaches the far end of the bowel, which is needed to examine the whole colon.

      The standard

      National minimum standard: 90% · aspirational target: 95%

    • Average withdrawal time

      14minutes

      and above 10 minutes in every quarter

      The time spent carefully examining the bowel lining on the way out, when most polyps are found.

      The standard

      National minimum standard: mean of at least 6 minutes · aspirational target: mean of at least 10 minutes

    • Polyp detection rate

      53%

      Polyps can develop into bowel cancer, so finding and removing them matters.

      The standard

      National minimum standard: 15% · aspirational target: 20%

    • Polyp retrieval

      Around99%

      How often removed polyps are recovered and sent to the laboratory. The results guide any further treatment or surveillance.

      The standard

      National minimum standard: 90%

    • Comfort

      Fewer than2%

      with moderate or severe discomfort

      Over 98% of procedures were assessed as causing no more than mild discomfort. Around a third were performed without sedation.

      The standard

      BSG aim: fewer than 10% of patients with moderate or severe discomfort

    These figures are from Dr Ahmad’s own audited data and are not a guarantee of individual outcomes.

    Book a consultation

    Your specialist, Dr Ahmir Ahmad

    Consultant Gastroenterologist & Endoscopist

    Dr Ahmad qualified in medicine from University College London in 2010. He completed a four-year specialist endoscopy fellowship at St Mark’s Hospital from 2018 to 2022, and a PhD at Imperial College London in 2023 focused on improving the quality and efficiency of colonoscopy. Colonoscopy is often the best way to find the cause of rectal bleeding, a change in bowel habit, bloating or abdominal pain. His specialist interests include complex polyp removal, endoscopic mucosal resection (EMR) and optical diagnosis. He continues to perform colonoscopy at St Mark’s, the National Bowel Hospital, and has carried out more than 4,500 procedures.

    • Qualifications MBBS, BSc, MRCP, PhD
    • Professional registration GMC 7090128 · Specialist Register
    • Practises at Welbeck London · Nuffield Health Brentwood Hospital · Spire Hartswood Hospital · St Mark’s TrustPlus, Northwick Park Hospital
    • Experience 4,500+ procedures

    Medically reviewed by Dr Ahmir Ahmad. Last reviewed 20 October 2026.

    Testimonial

    What patients say

    How patients felt before, during and after their procedure.

    “Dr Ahmad is an extremely professional and knowledgeable doctor that instills confidence in his patient. Despite an unexpected event during a colonoscopy he was calm and reassuring and I cannot fault his aftercare.”

    Colonoscopy patient Verified · Doctify

    “I have absolute faith in Dr Ahmad, he is concise and caring at the same time and always checks to make sure that you know what’s what.”

    Colonoscopy patient Verified · Doctify

    “Dr Ahmir made me feel so comfortable and safe and informed throughout my consultations and procedure. I was very nervous but his professionalism and care made the entire process very comfortable and I would highly recommend him. Thank you!”

    Colonoscopy patient Verified · Doctify

    “Dr Ahmad was friendly and professional and very reassuring from the first moment of my consultation, taking time to explain everything. This continued on my procedure day and along with Dr Ahmad, his team at One Wellbeck were all kind and provided the support I needed when I was nervous. Everyone was really great.”

    Colonoscopy patient Verified · Doctify

    “Dr Ahmad is very professional and has excellent personal skills. I felt immediately impressed and assured on his high level of expertise. Took a good amount of time to throughly look at my issues. Then reacted immediately with a quick plan to move forward. Excellent professional.”

    Colonoscopy patient Verified · Doctify
    Read all 22 reviews on Doctify Book a consultation

    Frequently asked questions

    • Rectal bleeding means passing blood from your back passage. You might see it on the toilet paper, in the toilet bowl or mixed in with your stool. It’s common, and most of the time the cause is minor, but it’s always worth getting checked.

    • The main sign is blood when you open your bowels. It may be bright red or dark, and it can come with pain, itching, a change in bowel habit, bloating, tiredness or unexplained weight loss.

    • Haemorrhoids (piles) and small tears in the skin of the back passage (anal fissures) are the most common causes. Polyps, bowel inflammation, infection and, less often, bowel cancer can also cause bleeding, which is why it’s worth having it looked at.

    • Bright red blood usually comes from low down, near the back passage. Dark red or black, tar-like stools can mean bleeding from higher up in the bowel or stomach. The colour is only a clue, so it can’t tell you the cause on its own.

    • See a doctor promptly if the bleeding keeps coming back or lasts more than a few days, or if you have a change in bowel habit, unexplained weight loss, tiredness or anaemia, or a family history of bowel cancer. Heavy bleeding, dizziness, fainting or severe pain need urgent help, so call 999 or go to A&E.

    • No. Many cases are caused by haemorrhoids or a small tear and settle with simple treatment. But you can’t tell the cause by looking, so any bleeding that is new, keeps happening or comes with other symptoms should be checked.

    • See a doctor if you notice blood more than once, if it doesn’t settle within a few days, or if you have any of the warning signs above. Even a single episode is worth mentioning if you’re over 40 or you’re worried about it.

    • Your doctor will ask about your symptoms and medical history and may examine you. You may also have blood tests, for example to check for anaemia. If the cause isn’t clear, you may be advised to have a colonoscopy.

    • Not everyone does. A colonoscopy is usually recommended if you’re older, if the bleeding is persistent, or if you have other symptoms or risk factors. It lets the doctor see the whole lining of the large bowel, find the source of the bleeding and take biopsies if needed.

    • Treatment depends on the cause. Haemorrhoids and fissures often improve with diet changes, medicines or minor procedures. Polyps can usually be removed during a colonoscopy, and bowel inflammation is treated with medication. Once the cause is clear, Dr Ahmad will talk you through the options.

    Get in touch

    Have a question about rectal bleeding? We’re happy to help.

    Get in touch

    Have a question about colonoscopy? We’re happy to help.

    Advice after your procedure

    Office hours

    Contact Dr Ahmad’s secretary on 07435 081678 or at clinic@drahmirahmad.com.

    • Monday – Friday 9:00am – 5:00pm

    Out of hours

    Contact the hospital where you were treated for advice:

    If you can’t get through to the hospital, call NHS 111.

    In an emergency, call 999 or go to A&E, and tell them about your recent procedure.

    Worried about rectal bleeding?

    See Dr Ahmad to find the cause at Welbeck London in Marylebone, Nuffield Health Brentwood Hospital or Spire Hartswood Hospital in Brentwood, Essex, or St Mark’s TrustPlus at Northwick Park Hospital in Harrow. Consultations are available in person, by video or by phone.

    Book a consultation
    Call 07435 081678