This document discusses abdominal tuberculosis, noting that it can involve any part of the gastrointestinal tract. It spreads most commonly to the ileocaecal region. Presentation can be varied and nonspecific. Diagnosis involves ascitic fluid analysis, colonoscopy, and biopsy showing caseating granulomas. Treatment involves antitubercular therapy for at least 6 months. Abdominal tuberculosis incidence will likely rise with the HIV epidemic.

1. ABDOMINAL TUBERCULOSIS

2. Introduction
 TB can involve any part of GIT from mouth to
anus, peritoneum & pancreatobiliary system.
 Very varied presentation possible ⇒
TB of GIT- 6th most frequent extrapulmonary site.

3. HIV & TB
 Before era of HIV infection > 80% TB
confined to lung
 Extrapulmonary TB increases with HIV
 40 –60% TB in HIV+ pt - extrapulmonary
 Globally, propotion of coinfected pt > 8 %
 ~ 0.4 million people in India coinfected.
 16.6% abdominal TB pt in Bombay HIV +.

4. Incidence & severity of
abdominal TB will increase with
the HIV epidemic

5. Pathogenesis
 Mechanisms by which M. tuberculosis reach the
GIT:
 Hematogenous spread from primary lung focus
 Ingestion of bacilli in sputum from active pulmonary focus.
 Direct spread from adjacent organs.
 Via lymph channels from infected LN

6.  Most common site - ileocaecal region
 Increased physiological stasis
 Increased rate of fluid and electrolyte absorption
 Minimal digestive activity
 Abundance of lymphoid tissue at this site.

7. Distribution of tuberculous lesions
Ileum > caecum > ascending colon > jejunum
>appendix > sigmoid > rectum > duodenum
> stomach > oesophagus
 More than one site may be involved

8.  Peritoneal involvement occurs from :
 Spread from LN
 Intestinal lesions or
 Tubercular salpingitis
 Abdominal LN and peritoneal TB may occur without
GIT involvement in ~ 1/3 cases.

9. Peritoneal tuberculosis occurs in 3 forms.
• Wet type - ascitis.
• Encysted (loculated) type - localized swelling.
• Fibrotic type - masses composed of mesenteric &
omental thickening, with matted bowel loops.

10. Clinical Features
 Mainly disease of young adults
 ~ 2/3 of pt. are 21-40 yr old
 Sex incidence equal.
 Clinical presentation → Acute / Chronic / Acute on
Chronic.

11.  Constitutional symptoms
 Fever (40%-70%)
 Weight loss (40%-90%)
 Anorexia
 Malaise
 Pain (80%-95%)
 Colicky (luminal stenosis)
 Continous ( LN involvement)
 Diarrhoea (11%-20%)
 Constipation
 Alternating constipation and diarrhoea

12. Tuberculosis of esophagus
 Rare ~ 0.2% of total cases
 By extension from adjacent LN
 Low grade fever / Dysphagia / Odynophagia /
Midesophageal ulcer
 Mimics esophageal Ca

13. Gastroduodenal TB
 Stomach and duodenum each ~ 1% of total cases
 Mimics PUD - shorter history, non response to t/t
 Mimics gastric Ca.
 Duodenal obstruction - extrinsic compression by tuberculous
LN
 Hematemesis / Perforation / Fistulae / Obstructive jaundice
 Cx-Ray usually normal
 Endoscopic picture - non specific

14. Ileocaecal tuberculosis
 Colicky abdominal pain
 ‘Ball of wind’ rolling in abdomen
 Borborygmi
 Right iliac fossa lump - ileocaecal region,
mesenteric fat and LN

15. Obstruction
 Most common complication
Pathogenesis
 Hyperplastic caecal TB
 Strictures of the small intestine--- commonly multiple
 Adhesions
 Adjacent LN involvement → traction, narrowing and fixation of
bowel loops.

16. Perforation
 2nd commonest cause after typhoid
 Usually single and proximal to a stricture
 Clue - TB Chest x-ray, h/o SAIO
 Pneumoperitoneum in ~ 50% cases

17. Malabsorption
 Pathogenesis
 bacterial overgrowth in stagnant loop
 bile salt deconjugation
 diminished absorptive surface due to ulceration
 involvement of lymphatics and LN

18. Segmental / Isolated colonic tuberculosis
 Involvement of the colon without involvement of the
ileocaecal region
 9.2% of all cases
 Multifocal involvement in ~ 1/3 (28% to 44%)
 Median symptom duration <1 year

19. Colonic tuberculosis
 Pain --- predominant symptom ( 78%-90% )
 Hematochezia in < 1/3 - usually minor
Overall, TB accounts for ~ 4% of LGI bleeding
 Other features--- fever / anorexia / weight loss /
change in bowel habits

20. Rectal and Anal Tuberculosis
 Hematochezia - most common symp. Due to mucosal
trauma by stool
 Constitutional symptoms
 Constipation
 Rectal stricture
 Anal fistula – usually multiple

21. Diagnosis and Investigations
 Non specific findings---
 Raised ESR
 Positive Mantoux test
 Anemia
 Hypoalbuminaemia

22. Immunological Tests
 ELISA
Response to mycobacteria variable & reproducibility poor
Value of immunological tests remain undefined

23. Ascitic fluid examination
 Straw coloured
 Protein >3g/dL
 TLC of 150-4000/µl, Lymphocytes >70%
 SAAG < 1.1 g/dL
 ZN stain + in < 3% cases
 + culture in < 20% cases

24. Adenosine Deaminase (ADA)
Aminohydrolase that converts adenosine  inosine
 ADA increased due to stimulation of T-cells by
mycobacterial Ag
 Serum ADA > 54 U/L
 Ascitic fluid ADA > 36 U/L
 Ascitic fluid to serum ADA ratio > 0.985
 Coinfection with HIV → normal or low ADA

25. Colonoscopy
Colonoscopy - mucosal nodules & ulcers
 Nodules
 Variable sizes (2 to 6mm)
 Non friable
 Most common in caecum especially near IC valve.
 Tubercular ulcers
 Large (10 to 20mm) or small (3 to 5mm)
 Located between the nodules
 Single or multiple
 Transversely oriented / circumferential contrast to Crohns
 Healing of these ‘girdle ulcers’→ strictures
 Deformed and edematous ileocaecal valve

32. Colonoscopic Diagnosis
 8 –10 Bx from ulcer edge
 Low yield on histopath as mainly submucosal disease
 Granulomas in 8%-48%
 Caseation in ~ 1/3 (33%-38%) of + cases
 AFB stains - variable
 Culture positivity in 40%
 Combination of histology & culture ⇒ diagnosis in 60%

33. Laparoscopic Findings
 Thickened peritoneum with tubercles -
 Multiple, yellowish white, uniform (~ 4-5mm) tubercles
 Peritoneum is thickened & hyperemic
 Omentum, liver, spleen also studded with tubercles.
 Thickened peritoneum without tubercles
 Fibro adhesive peritonitis
 Markedly thickened peritoneum and multiple thick adhesions
Caseating granulomas + in 85%-90% of Bx

35. Management
 ATT for at least 6 months including 2 months of Rif, INH,
Pzide and Etham
 However in practice t/t often given for 12 to 18 months
 2 recent reports → obstructing lesions may relieve with ATT
alone
However most will need surgery