Meckel's diverticulum is derived from an abnormal persistence of the proximal part of the vitelline duct.

It is situated  80cm proximal to the ileocaecal junction  on the antimesenteric border.

Macroscopically, it is a small pouch or a blind segment
which varies in length from less  than 1cm to 8cm , and lumen diameter is greater than that of the ileum.

This is a true diverticulum containing all three layers of the bowel wall (mucosa, submucosa and muscularis propra).

Histology reveals normal small intestinal mucosa. Often heterotopic rests of gastric and colonic mucosa  or pancreatic tissue may be present.

 Image1:click here (webpath)  ;  Image2: click here

Complications of Meckel's diverticulum:

1) inflammation 

2) perforation, 

3) vesiculodiverticular fistula,

4) ulceration (peptic ulceration occurs in the ileum adjacent to the heterotopic gastric mucosa)

5) haemorrhage (painless bleeding is common symptom in diverticulitis)

6) intussusception 

7) intestinal obstruction from attached bands and tumours.

8)Carcinoid tumours have been often reported.

9)Other tumours arising in Meckel's diverticulum include- adenocarcinoma, villous adenoma, leiomyoma, leiomyosarcoma, malignat melanoma.

Visit: Lesions causing small bowel obstruction and bleeding  ; Ischemic bowel disease . 

Histopathological image of Meckel's diverticulum

Heterotopic rests of gastric mucosa (low power)

Heterotopic rests of gastric mucosa (high power)