Case 20: Bloody Stools. Expert comment by Dr Aruchuna Mohanaruban

Thanks to everyone who contributed to the discussions about Mr Aziz a 26 year-old Bangladeshi gentleman who presents to the emergency department with a 4 week history of bloody diarrhoea.


You can see the highlights of the discussion on Twitter in the storify.

This week’s question setter & expert is Dr Aruchuna Mohanaruban, Gastroenterology ST5, Royal London Hospital

Information available at the start of the week:

He reports opening his bowels up to 8 to 10 times a day and this is associated with the passage of dark red blood which is mixed in with the stool.

The triage nurse in the emergency department records his observations on admission and gives them to you on a piece of paper. These are as follows:

Temperature: 38.9 C

HR: 100 bpm

BP 120/70 mmHg

RR: 18 breaths/min

SPO2: 99% on room air

His initial blood tests are already back from the lab:
Hb 9.7 g/dL
WCC 14.0 x109/L
Plt 557 x109/L
Na 146 mmol/L
K 3.1 mmol/L
Urea 7.9 mmol/L
Creatinine 78 mmol/L
Bil 25 umol/L
ALT 30 U/L
ALP 75 U/L
Albumin 30 g/L
INR 1.1
CRP 35 mg/L

ESR 37 mm/hr

Question 1. What further information would you like to know from Mr Aziz’s history and examination? 

Further information released during the week:


He is complaining of generalised cramping abdominal pain, mainly in the LIF, made better by defecation.

He has lost 3kg of weight in the past month, and he is worried to eat as this seems to make his diarrhoea worse so he has resorted to just drinking liquids over the past week.

There is no history of foreign travel

No family history of inflammatory bowel disease

He does not have any joint pains, rash or ocular symptoms.




He does not take any regular medication.


He is a non smoker and does not drink any alcohol. He works as an accountant and lives with his parents. He has not travelled.


He is comfortable but has dry mucous membranes. His abdomen is soft with some mild discomfort on palpation on the left side. There is no organomegaly. Bowel sounds are normal. There are no rashes, eye problems or any joint swelling.

Investigations reveal:

Abdo x-ray:

Screen Shot 2014-03-08 at 11.11.57

Further questions discussed on Twitter:

You decide to admit him to hospital after considering the truelove and witts criteria.

What investigations would you arrange?

–        Blood cultures are taken as his temperature on admission was >38C. These show no growth after 48 hrs.

–        Stool cultures do not grow any organisms and are negative for clostridium difficile.

–        Stool chart is recorded from day one of admission

–        Abdominal X-ray – shows oedematous descending colon with ”thumb printing” but no toxic megacolon.

Question 2:  Which urgent investigation does Mr Aziz need next?

Urgent Flexible Sigmoidoscopy

Screen Shot 2014-03-14 at 10.04.06

Question 3: What is the Mayo Score?

Question 4: How should he be managed acutely?

Expert Comment

Key points:

  1. How to assess a patient presenting with acute diarrhoea using the true-love and witt criteria
  2. Develop a systematic approach to investigating a patient with bloody diarrhoea
  3. Daily AXR is essential to recognise complications from colitis including toxic megacolon
  4. Involve the surgical team early


Dr Aruchuna Mohanaruban , ST5 Gastroenterology, Royal London Hospital, says:

This case highlights the key investigation and management steps needed when assessing a patient with suspected acute ulcerative colitis.


When taking a history from a patient presenting with diarrhoea it is important to clarify what they mean by the term “diarrhoea”, is this an increased stool frequency (number of times), change in stool consistency (loose) or both? Of course it is important to illicit how long they have had the diarrhoea for and whether they have had this before.

With regards to rectal bleeding, it is important to ask the colour and amount, and whether it is separate or mixed in with the stool. Dark red bleeding would suggest the bleeding is more proximal. Blood which is separate from the stool, or on wiping on the tissue, may be more suggestive of a haemorrhoid or fissure.

A detailed travel history is important as e-coli, salmonella, campylobacter and shigella are common culprits causing diarrhoea in the returning traveller. Do not forget to ask for symptoms of extraintestinal manifestations of inflammatory bowel disease (IBD) as this condition does not only affect the gastrointestinal tract. It is also associated with dermatological, ocular problems, arthropathies, gallstones and primary sclerosing cholangitis.

A family history of IBD will increase your index of suspicion that this patient may have a new diagnosis of IBD. Certain medication can precipitate colitis particularly non steroidal anti-inflammatory drugs (NSAIDs).
Smoking is protective for ulcerative colitis but exacerbates Crohn’s disease for reasons which are still poorly understood.

True-love and Witts Criteria

Screen Shot 2014-03-14 at 10.13.25

The true-love and witts criteria is used to grade the severity of ulcerative colitis. Immediate admission to hospital is warranted for all patients fulfilling the Truelove and Witts’ criteria for severe colitis.

Investigations required

–        Stool culture for microscopy culture and sensitivity including clostridium difficile

–        Stool for ova, cysts and parasites if history of foreign travel

–        Stool chart (frequency; colour/blood content; estimate of volume)

–        Bloods (repeat daily): FBC; CRP; U&Es, LFTs, Magnesium and Calcium

–        Blood culture if temp>38C

–        Abdominal X-ray. Thumb printing is a sign of thickened oedematous mucosal folds suggesting active colitis. Toxic megacolon is a dilated colon (>6 cm in diameter) which can be seen as a complication of severe ulcerative colitis which if left untreated can lead to perforation.

–        Urgent flexible sigmoidoscopy with biopsies. A colonoscopy should NOT be done in acute colitis as the risk of causing pain and perforation is high.

Differential diagnosis:

– The endoscopic image shows confluent superficial ulceration and loss of mucosal architecture affecting the left side of the colon. Ulcerative Colitis is the main differential here. Inflammation tends to be continuous compared to in Crohns disease where there is patchy inflammation. Crohns usually affects the small bowel, commonly the terminal ileum. The Mayo score can be used to grade the severity of the endoscopic findings.

– Infective Colitis: These include bacterial infections (C.diff; Campylobacter; Salmonella; Shigella; E.coli0157), viral infection (if patient already immunocompromised such as cytomegalovirus) and amoeba (especially if there is a positive travel history).

– Ischaemic colitis is less likely here in a young patient with minimal abdominal pain.


The treatment should be as follows:

1) Monitor & correct fluid and electrolyte status

2) Start intravenous steroids: Hydrocortisone 100mg IV QDS [and prophylactic low molecular weight heparin – these patients are at high risk of thrombosis] and consider nutritional supplementation.

3) Assess status of patient after 3 days of IV steroids. The options now will be either a colectomy (removal of his colon) or continuation of medical treatment and this will depend on how he is responding to treatment.

If he is responding poorly i.e. severe bleeding and diarrhoea, toxic megacolon, perforation or sepsis = Urgent Colectomy.

If he is stable then there needs to be a discussion between patient, colorectal surgical team and medical team to decide the preferred next step. The options here will be further immunosuppressant therapy with infliximab (TNF- α inhibitor) or ciclosporin. Again if this therapy fails, the only option will be to proceed to colectomy and so it is vital to involve the surgical team early when the patient first presents to hospital.

I have purposely not gone into further details of medical and surgical management as this is beyond the scope of this case study but if you would like further information on treatment please refer to the resources section.

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