1. Diarrhoea Lent term year 2

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: T37 4 C, ill-defined tender mass in RIF PR: painful, with anal fissure PMH: arthritis affecting various joints which resolved, episode of uveitis 1 year ago

3. Differential diagnosis?

4. Wide differential diagnosis Infective Malabsorption Malignancy Inflammatory Iatrogenic Motility disorder/functional

5. 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

6. 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)

7. 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

8. Stool microscopy:giardia

9. And yet more… Whipple’s disease Tropheryma whippelii. Tropical. Causes malabsorption Tropical sprue. Another cause of malabsorption ??infective organism

10. Don’t forget worms roundworm (Ascaris lumbricoides) Can cause intestinal obstruction whipworm (Trichuris trichiura) and hookworm (Ancylostoma duodenale and Necator americanus).

11. Roundworms resected

12. Malabsorption Coeliac disease Cystic fibrosis (lack pancreatic enzymes) Lactose intolerance

13. Malignancy Carcinoma of large bowel Carcinoid tumour: neuroendocrine tumour usually found in appendix of small bowel May produce serotonin and cause carcinoid syndrome: diarrhoeadiarrhoea flushing of the skin, wheezing (similar to asthma), loss of appetite, weight loss. Benign villous adenoma

14. 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

15. Crohn’s disease

16. iatrogenic Short bowel syndrome Laxatives Radiotherapy Chemotherapy: antibiotics, cytotoxic drugs

17. Motility disorder/function Diabetic neuropathy Ischaemic bowel Hyperthyroidism IBS Overflow (associated with constipation)

18. How would you investigate this patient?

19. Possible investigations: Stool culture (negative) Blood tests: Hb 10.0g/dl ESR 60 mm/hr Albumin: 28g/dl WCC- 14,000

20. CT scan:

21. Barium follow-through

22. Barium enema

23. Nuclear scanning: white cell scanning

24. So the diagnosis was………!