Chapter17: INTESTINES:Other Causes of Chronic Colitis

Question 1

Other Causes of Chronic Colitis

Answer 1

• DIVERSION COLITIS
• MICROSCOPIC COLITIS
• GRAFT-VERSUS-HOST DISEASE

Question 2

What is a Hartmann’s pouch?

Answer 2

Surgical treatment of ulcerative colitis, Hirschsprung disease, and other intestinal disorders sometimes requires creation of a temporary or permanent ostomy and a blind distal segment of colon, such as a Hartmann’s pouch, from which the normal fecal flow is diverted.

Question 3

What is diversion colitis?

Answer 3

Colitis can develop within the diverted segment, particularly in ulcerative colitis patients

Surgical treatment of ulcerative colitis, Hirschsprung disease, and other intestinal disorders sometimes requires creation of a temporary or permanent ostomy and a blind distal segment of
colonsuch as Hartmann’s pouch, from which the normal fecal flow is diverted.

Question 4

What is most striking feature of diversion colitis is the?

Answer 4

.Besides mucosal erythema and friability, the most striking feature of diversion colitis is the development of numerous mucosal lymphoid follicles ( Fig. 17-39A ).

Increased numbers of lamina propria
lymphocytes, monocytes, macrophages, and plasma cells may also be present.

In severe cases
the histopathology may resemble IBDandinclude crypt abscesses, mucosal architectural
distortion, or, rarely, granulomas.

Question 5

What is the pathogenesis in Diversion colitis?

Answer 5

The pathogenic mechanisms responsible for diversion colitis are not well understood, but changes in the luminal microbiota and diversion of the fecal stream
that provides nutrients to colonic epithelial cells have been proposed.

Consistent with this, enemas containing short-chain fatty acids, a product of bacterial digestion in the colon and an important energy source for colonic epithelial cells, can promote mucosal recovery in some
cases.

The ultimate cure is reanastomosis of the diverted segment.

Question 6

What is the proposed treatment for Diversion Colitis?

Answer 6

Consistent with this, enemas containing short-chain fatty acids, a product of bacterial digestion in the colon and an important energy source for colonic epithelial cells, can promote mucosal recovery in some
cases.

The ultimate cure is reanastomosis of the diverted segment.

Question 7

Answer 7

FIGURE 17-39 Uncommon causes of colitis.

• A, Diversion colitis in a Hartmann’s pouch. Note the large lymphoid aggregates with germinal centers.
• B, Collagenous colitis with intraepithelial lymphocytes and a dense subepithelial collagen band.
• C, Lymphocytic colitis

Question 8

Microscopic colitis encompases two entities, what are these?

Answer 8

1. collagenous colitis and
2. lymphocytic colitis.

Question 9

What is microscopic colitis?

Answer 9

These idiopathic diseases both present with chronic, nonbloody, watery diarrhea without weight loss.

Radiologic and endoscopic studies are typically normal.

Question 10

Collagenous colitis, which occurs primarily in what age?

Answer 10

primarily in middle-aged and older women, is

Question 11

What is characteristic of Collagen Colitis?

Answer 11

characterized by the presence of a dense
subepithelial collagen layer, increased numbers of intraepithelial lymphocytes, and a mixed
inflammatory infiltrate within the lamina propria ( Fig. 17-39B ).

Question 12

What is the histologcal appearance of Lymphocytic colitis?

Answer 12

Lymphocytic colitis is histologically similar, but the subepithelial collagen layer is of normal thickness and the increase
in intraepithelial lymphocytes may be greater, frequently exceeding one T lymphocyte per five
colonocytes ( Fig. 17-39C ).

Question 13

Lymphocytic colitis shows a strong association with what diseases?

Answer 13

• with celiac disease
• and autoimmune diseases, including:
  
  • thyroiditis,
  • arthritis, and
  • autoimmune or lymphocytic gastritis.

Question 14

What is the histological finding in graft-versus-host disease?

Answer 14

Graft-versus-host disease occurs following allogeneic bone marrow transplantation. The small
bowel and colon are involved in most cases. Although graft-versus-host disease is secondary to
donor T cells targeting antigens on the recipient’s GI epithelial cells, the lamina propria
lymphocytic infiltrate is typically sparse.

Epithelial apoptosis, particularly of crypt cells, is the
most common histologic finding.

Rarely, total gland destruction occurs, although endocrine cells may persist. Intestinal graft-versus-host disease often presents as a watery diarrhea.