Change in Bowel Habit Practice Station

Author – Fatima Wasti  Reviewer – Sofia Hu   Editor – Ansaam El-Sherif 

Last updated 10/06/23

Table of Contents

How to Use


  1. Read the brief below (1 minute). 
  2. Take a history (6 minutes).
  3. Answer viva questions (3 minutes).


  1. Familiarise yourself with the history & examination findings 
  2. After completing the history, viva the candidate

Candidate Brief

Jennifer is a 63-year-old woman who has presented to her GP with diarrhoea. Please take a history from her and formulate a management plan. You have 10 minutes.

Presenting complaint:

You are quite embarrassed about this, but you have come to the GP today because you have diarrhoea.

History of presenting complaint:

  • What do I mean by diarrhoea? Runny and watery stool.
  • Onset and duration: Gradually started 6 weeks ago. You have had an increasing need to go open your bowels, 3 times a day.
  • Progression: The diarrhoea has stayed constant for the last 6 weeks. You have started to go to the toilet more often than normal.
  • Character/colour: watery stools that are brown coloured.
  • Radiation: You have not noticed any blood or mucus in the stools. No change in colour or smell.
  • Associated features: below
  • Exacerbating relieving factors: You have not noticed anything to trigger the diarrhoea. You had some food from a takeaway restaurant a few weeks back before the diarrhoea. You are not sure if that is related.
  • Severity: This is starting to annoy you now, as you are having to get up quite a lot to go to the toilet all the time now. You’re worried you can’t go grocery shopping because of the fear you will need the toilet.

Normal bowels:

  • You normally open your bowels once a day, and you have solid brown stool which is never hard or painful to pass. You have suffered from diarrhoea before after eating at a funny restaurant a year ago. This is similar to the food poisoning diarrhoea you had a year ago.

Associated features:

  • Bloating: You have not noticed any bloating or masses in your abdomen. You have not had any difficulty passing flatulence.
  • Pain: You have not noticed any abdominal pain.
  • Weight loss: You have started a new diet recently and you do think you have lost some weight on your face because of it.
  • Exhaustion: The diarrhoea is tiring you out, but you are not feeling too fatigued.
  • Lasting urge: You have not had any urges to go to the toilet.
  • Swallowing/upper GI symptoms: No vomiting, no difficulties swallowing, no heart burn, no abdominal distension.
  • No mouth ulcers

Red flag symptoms:

  • No fever, no back pain, no rigors or night sweats.
  • You have noticed some weight loss which may be related to your diet. You are unable to quantify your weight loss
  • No rectal bleeding
  • No blood in stools
  • No abdominal or rectal mass

Systems Review

  • General: Pallor, fatigue
  • Respiratory: occasional shortness of breath, started 2 weeks ago, usually when you are walking long distances. It does not stop you from walking.
  • Cardiology: You have started to get a little light-headed when you stand up suddenly. This is new and has never occurred before.
  • Endocrinology/Neurology: No other relevant symptoms

Travel history:

  • No recent travel


  • Ideas: You are wondering if this is another episode of food poisoning, however you do feel that it has been going on for too long now so you’re starting to get a little worried.
  • Concerns: You’re worried it’s something more serious
  • Expectations: Nothing.

Past medical history:

  • Diabetes
  • Only if asked: You have just received your FIT test in the post however you have not had a chance to complete it.
  • Only if asked: You have not had a recent course of antibiotics or been admitted to hospital recently. (This is relevant to rule out clostridium difficile infection)

Past surgical history

  • Appendix removal 10 years ago due to appendicitis.

Drug history:

  • Metformin: Only if asked: this was started 1 year ago. This is important to ask as starting metformin can cause GI disturbance.
  • NKDA

Family history:

  • You were an orphan and an only child, so you did not know what diseases or cancers your parents had.

Social history:

  • You are an ex-smoker of 5 cigarettes a day for 3 years. You stopped smoking 1 year ago.
  • You have never taken any recreational drugs.
  • You drink red wine socially.
  • You are a retired school teacher.
  • You live alone


  • BP 98/60
  • HR 100
  • RR 12
  • O2 saturations: 98 %

General exam:

  • Inspection- appears comfortable at rest.
  • Hands-No peripheral stigmata of disease. CRT 3 seconds
  • Face- Conjunctival pallor. Mucus membranes appear slightly dehydrated.

Abdomen examination:

    • Abdomen slightly distended. Soft non-tender abdomen
    • No masses palpable. No hepatomegaly or splenomegaly.
    • Normal percussion

What are your top 3 differential diagnoses?

  1. Bowel cancer. The age, change in bowel habit, alongside the symptoms of anaemia and weight loss (albeit may be intentional) all suggest a diagnosis such as colorectal cancer.
  2. Diverticular disease: commonly presents as diarrhoea, however the absence of pain and blood in stool make this an unlikely diagnosis.
  3. Inflammatory bowel disease: This is least likely, as there has been no changes in diet, and a lack of systemic symptoms such as mouth ulcers or skin changes. However, some people with IBD do not develop their first flare until they are 60(1).

What other investigations would you do?


  • PR exam with a chaperone
  • Respiratory exam to examine her shortness of breath
  • Lying standing blood pressure

Laboratory investigations (2)(3)

  • Full blood count to assess for iron deficiency anaemia in case of bleeding from other sites
  • Urea and electrolytes to assess for dehydration as patient has had chronic diarrhoea
  • Liver function tests including albumin level, as liver pathology can be associated with inflammatory bowel disease, but also to rule out dehydration (albumin is high in dehydration and low in inflammation or malabsorption)
  • Calcium – calcium is usually raised in cancer conditions(4)
  • Vitamin B12 -to rule out anaemia
  • Red blood cell folate – to rule out anaemia
  • Ferritin to assess for iron deficiency anaemia
  • ESR to assess for inflammatory bowel disease
  • CRP to assess for inflammatory bowel disease
  • TSH -diarrhoea can also be caused by hyperthyroidism

Referral investigations

  • FIT test to check for occult blood in stools.
  • Faecal calprotectin to rule out IBD.
  • Consider CA125 testing however ovarian cancer is unlikely.
  • Consider carcinoembryonic antigen CEA testing (3) (marker for bowel cancer)
  • Colonoscopy and biopsy(5)
  • Consider stool sample for microbiology examination for ova, cysts and parasites (3).
  • Consider C.difficile testing

What would be your next steps as the GP to manage the patient?

An unexplained change in bowel habit for adults age >60 years should warrant a 2 week suspected cancer pathway referral for suspected colorectal cancer (6).

What are the bowel cancer screening guidelines?

People aged 60-74 years are offered bowel cancer screening using a faecal immunochemical test. Patients with a negative FIT test will return to normal routine testing every 2 years. Patients with a positive FIT test will need a colonoscopy (7).  

Describe the staging system for colorectal cancer?

TNM staging system (5) (9).

T-stage (tumour stage):  shows the depth of the tumour invading the bowel.

N-stage (nodes stage): shows the extent of the spread of the cancer to local lymph nodes. M-stage (metastasis stage):  shows whether there has been metastasis from the cancer.

What is the most common location for colorectal cancer?

The proximal colon (8).

What are the different surgical resections for colorectal cancer?

  • Right hemicolectomy for removal of cancers in the caecum, ascending and proximal transverse colon
  • Left hemicolectomy for removal of cancers in the distal transverse and descending colon.
  • High anterior resection for removing cancers in the sigmoid colon
  • Low anterior resection for removing cancers in the sigmoid colon and upper rectum
  • Abdomino-perineal resection for removing the rectum and anus
  • Hartmann’s procedure: for emergency removal of the rectosigmoid colon (9).
  1. Mayo clinic. Inflammatory bowel disease [Internet]. Mayo Clinic Staff; 2022 [cited 2023 06 04] Available from:,until%20their%2050s%20or%2060s
  2. National Institute for Health and Care Excellence. Diarrhoea-adult’s assessment [Internet] National Institute for Health and Care Excellence; Revised in 2021 [cited 2023 06 04] Available from:
  3. National Institute for Health and Care Excellence. Diarrhoea-adult’s assessment> Scenario: chronic diarrhoea (>4 weeks) [Internet] National Institute for Health and Care Excellence; Revised in 2021 [cited 2023 06 08] Available from:
  4. Labs test online. Calcium test [Internet]. Labs test online UK. Revised in 2020 [cited 2023 06 08] Available from:
  5. Teach Me Surgery. Colorectal Cancer [Internet]. Teach Me Surgery; 2021 [cited 2023 06 04] Available from:
  6. National Institute for Health and Care Excellence. Gastrointestinal tract (lower) cancers-recognition and referral> symptoms suggestive of gastrointestinal tract (lower) cancers [Internet] National Institute for Health and Care Excellence; Revised 2021 [cited 2023 06 04] Available from:
  7. National Healthcare Service. Bowel cancer screening overview [Internet] NHS 2021; [cited 2023 06 04] Available from:
  8. British Medical Journals. Colorectal Cancer [Internet] BMJ Publishing group 2023 [cited 2023 06 04] Available from:,%5B1%5D
  9. Zero to Finals. Bowel cancer [internet] Zero to Finals 2021 [cited  2023 06 04] Available from:

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