Diarrhoea

Lent term year 2

The Case: Mr JK aged 25• Loose, frequent motions for 2 years• Now presents with more severe diarrhoea

with bleeding and pain in the RIF• On examination: T374C, ill-defined tender

mass in RIF• PR: painful, with anal fissure• PMH: arthritis affecting various joints

which resolved, episode of uveitis 1 year ago

Differential diagnosis?

Wide differential diagnosis

• Infective

• Malabsorption

• Malignancy

• Inflammatory

• Iatrogenic

• Motility disorder/functional

Infections: viruses

• Rotavirus (most common cause in children in UK)

• Norwalk virus (of genus norovirus) occurs in outbreaks- the “Winter vomiting bug”

• Ebola virus- mortality 50-100%

• Enteric adenovirus- usually respiratory infection

Infections: bacteria• e.coli: 057:H7 one to avoid (enterotoxin)• Salmonella (raw chicken and eggs)• Schigella (bacillary dysentery) Infectivity dose

(ID) very low- 10-100• Vibrio Cholerae (nb John Snow 1854)• Clostridium perfringens (pig-bel) and difficile • Typhoid/paratyphoid (salmonelli typhi/paratyphi)• Bacillus cereus (beware pre-cooked rice)• Campylobacter (beware undercooked chicken)• Listeria- (avoid eating unpasteurised cheese in

pregnancy)

Infections: parasites• Amoebic dysentery: (Tropical) entamoeba

histolytica. Infective in cyst form

• Giardia lamblia (Giardiasis) Infective in cyst form Low ID. Can be caught in swimming pools

Stool microscopy:giardia

And yet more…

• Whipple’s disease Tropheryma whippelii.

Tropical. Causes malabsorption

• Tropical sprue. Another cause of malabsorption ??infective organism

Don’t forget worms

• roundworm (Ascaris lumbricoides) Can cause intestinal obstruction

• whipworm (Trichuris trichiura) and

• hookworm (Ancylostoma duodenale and Necator americanus).

Roundworms resected

Malabsorption

• Coeliac disease

• Cystic fibrosis (lack pancreatic enzymes)

• Lactose intolerance

Malignancy• Carcinoma of large bowel

• Carcinoid tumour: neuroendocrine tumour usually found in appendix of small bowel

• May produce serotonin and cause carcinoid syndrome: diarrhoea

flushing of the skin, wheezing (similar to asthma), loss of appetite, weight loss.

• Benign villous adenoma

Inflammatory bowel disease

• Crohn’s disease. Can affect multiple sites from lips to anus. Can affect full thickness of bowel with fistula formation. Can get “skip lesions”. Often affects terminal ileum

• Ulcerative colitis Colon and rectum only- rectum in 95% cases

Crohn’s disease

iatrogenic

• Short bowel syndrome

• Laxatives

• Radiotherapy

• Chemotherapy: antibiotics, cytotoxic drugs

Motility disorder/function

• Diabetic neuropathy

• Ischaemic bowel

• Hyperthyroidism

• IBS

• Overflow (associated with constipation)

How would you investigate this patient?

Possible investigations:

• Stool culture (negative)

• Blood tests:

Hb 10.0g/dl

ESR 60 mm/hr

Albumin: 28g/dl

WCC- 14,000

CT scan:

Barium follow-through

Barium enema

Nuclear scanning: white cell scanning

So the diagnosis was………!