1. DEFNITION Occult gastrointestinal bleeding is defined as
gastrointestinal bleeding that is not visible to the patient or
physcian,resulting in either a positive fecal occult blood test,or
iron deficiency anemia with or without a positive fecal occult
blood test.
2. Obscure gi bleed = It refers to recurrent bleeding in which
a source is not identified after EGD, Colonoscopy, and small bowel
radiography. OBSCURE OCCULT= as manifested by recurrent IDA and /
or recurrent positive FOBT. OBSCURE OVERT = recurrent passage of
visible blood with melena or hematochezia
3. CAUSES OF OCCULT GI BLEEDING MASS LESIONS; CARCINOMA( any
site). Large (>1.5 cm) adenoma (any site). INFLAMMATION. Erosive
esophagitis ulcer (any site) Erosive gastritis Cameron lesions (
linear erosions within a hiatus hernia). Crohns disease Celiac
disease Ulcerative colitis.
5. Surreptitious bleeding Haemoptysis Oropharyngeal bleeding.
OTHER CAUSES Haemosuccus pancreaticus Haemobilia Long distance
running.
6. ETIOLOGY OF OCCULT BLEEDING Age 40 years; Vascular ectasia
,M/C cause NSAID induced ulcers.
7. HISTORY AND PHYSCIAL EXAM. A targeted history and physcial
exam. Should be performed. Abdominal pain with aspirin or other
NSAID use ,suggests ulcerative mucosal injury. Anticoagulants or
antiplatelet medication may precipitate bleeding in an undiagonised
lesion. Family history of GI bleeding may suggest HHT. (associated
with vascular lesions on lips tongue or palms) Blue rubber bleb
navus syndrome(a syndrome with venous malformations in the GIT,soft
tissue and skin).
8. History of gastric bypass surgery ; may suggest impaired
iron absorption. H/O stigmata of liver disease suggests portal
hypertensive gastropathy. SKIN Signs; Dermatitis herpetiformis >
Celiac disease Erythema Nodosum(painful erythematous nodules seen
in >Crohns disease. Blue rubber bleb navus syndrome(a syndrome
with venous malformations in the GIT,soft tissue and skin).
Freckles on lips and in mouth (peutz jeghers syndrome).
Hyperextensible joints and ocular and dental abnormalities >S/O
Ehlers danlos syndrome.
9. DIAGNOSTIC STUDIES Upper GI Bleeding (identified as source
of bleeding proximal to the ampulla of vater) can be dx.by EGD.
Proximal small bowel bleeding >can b detected by push
enteroscopy which reaches the proximal jejunum. Bleeding of mid and
distal small bowel can be > can be detected with Capsule
endoscopy, Deep enteroscopy and CT Enterography. Lower GI Bleeding
(Colonic bleeding) can be detected with colonoscopy.
10. DIAGNOSTIC STUDIES EGD and Colonoscopy > Bleeding source
in 48-71 % pt. In recurrent bleeding > repeat OGD and
Colonoscopy may find the missed lesion in 35% of those who had
negative initial findings. Capsule endoscopy >dx.yield 63-74%.
In Meta analysis of 14 studies ; Dx.yield of Capsule endoscopy was
superior to push enteroscopy (63 vs 28 %) and Barium studies (42 vs
6 %).
11. Fecal occult blood testing Guaiac-based tests: Uses a
chemical indicator that shows a colour change in the presence of
blood in stool. The pseudoperoxidase activity of hemoglobin turns
the guaiac compound blue in the presence of hydrogen peroxide.
IMMUNO CHEMICAL test ( FIT ); It is more specific ,detects only
human hemoglobin, ;uses antibodies directed against human
hemoglobin to detect blood in the stools. Positive results indicate
abnormal bleeding from lower intestine ,bcos blood from lower sites
is less degraded during transit For FOBT + 2ml blood in stool is
necessary. Two samples of each of 3 consecuative (daily )
stools.
12. CAPSULE ENDOSCOPY. Permits exam. 0f small intestinal mucosa
using wireless image capturing technology. Noninvasive method to
evaluate the entire length of small bowel. Can identify vascular
ectasia ,ulcers and masses in small bowel. CAPSULE= Size 2.6
cm,weight 3.5 g. COMPARTMENTS= Metal oxide silicon image sensor,
Light emitting diode (led) Aerial belt with 8 aerials which
collects signal from the capsule. Software for analysis.
13. INDICATIONS OF CE. Crohns disease Celiac disease
Immunoproliferative small intestinal disease (IPSID) Polyposis
Small intestinal tumor like carcinoid and lymphoma. Recurrent
abdominal pain with diarrhea. Obscure GI BLEED (after negative EGD
and Colonoscopy ) Recurrent iron deficiency anemia.
14. CAPSULE ENDOSCOPY ADVANTAGES; Noninvasive Disposable
DISADVANTAGES; Cost Inaccurate localization of the site of
bleeding. Capsule retension