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View Full Version : BILHARZIASIS OF THE COLON(Etiology-Pathology-Clinical picture-Investigations-Treatment)



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05-03-2008, 05:22 AM
m Causative Organism:Schistosoma mansoni.
m Epidemiology:
Endemic in Egypt especially in lower Egypt why?
As it lives in flattened snails which floats with water of the Nile to lower Egypt while snail of Schistosoma haematobium is conical sinks into the bottom.
How can schistosoma reach the colon?
1- The cercaria enter to venous circulation through skin.
2- When it reach the heart it will be pumped to all organs of the body.
3- All cercaria will die except those reaching the liver, where it finds its nourishment till reach the adult worms.
4- The adult worms leave the liver through the portal vein "swimming against blood stream".
5- It usually reach the Lt. side of the colon. WHY?
a- Weak blood flow "easier to swim"
b- Less concentration of antibilharzial drugs due to lower vascularity than Rt. side.
6- Schistosoma haematobium only reach urinary tract through the recto-vesical venous plexuses. WHY?
As its ova is smaller in size with terminal spine.
m Pathology:
The adult worms in the rectal venous plexus lay its eggs which either ® circulate with the blood stream to reach the liver resulting in bilharzial periportal fibrosis or penetrate the wall of the colon giving two types of lesions:
1- Submucosal lesions: due to deposition of ova in the submucosa.
® Bilharzial polyps. ® Bilharzial ulcers.
2- Subserosal lesions:
due to deposition of ova in the subserosa with 2ry infection.
® Bilharzial granuloma
® Bilharzial pericolic mass "due to fat deposition on top of infection"
m Clinical Picture:
1- Bleeding per rectum causing anemia. 2- Tenesmus
3- Mass in Lt. iliac fossa involving colon usually without obstruction.
4- P. R. examination ® Bilharzial polyps, (sessile or pedunculated).
m Complications:
1- Anaemia due to chronic blood loss.
2- Rectal prolapse due to tenesmus, straining and weight of polyps.
3- Bilharzial pericolic abscess due to 2ry infection ® Anal fistula .
4- Fibrosis rarely give colonic obstruction.
m Treatment:
1- Anti Bilharzial drugs for early cases.
2- Fulguration of Bilharzial polyps by colonoscope.
3- Bilharzial pericolic mass is difficult to excise ® leave it if it gives obstruction ®do proximal colostomy and give medical treatment of Bilharziasis may cure the mass within 6 months.
SOURCE: DR. AYMAN SALEM'S BOOK
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