Chapter Summary continued

Peptic ulcers are ulcers of the distal stomach and proximal duodenum caused by gastric secretions (hydrochloric acid and pepsin) and impaired mucosal defenses. Duodenal peptic ulcers are more common than gastric ulcers.

Gastric carcinomas tend to be asymptomatic until late in their course and may show a variety of histologic patterns.

Volvulus is twisting of a segment of bowel on its vascular mesentery, resulting in intestinal obstruction and infarction. Intussusception is telescoping of a proximal segment of bowel into the distal segment. Incarcerated hernia is a segment of bowel that becomes imprisoned within a hernia. Hirschsprung disease is a congenital absence of ganglion cells in the rectum and sigmoid colon resulting in intestinal obstruction.

Celiac sprue is a hypersensitivity to gluten, resulting in loss of small bowel villi and malabsorption. Tropical sprue is a malabsorptive disease of unknown etiology affecting travelers to tropical regions, such as the Caribbean and South America. Whipple disease is a rare infectious disease involving many organs, including small intestines, joints, lung, heart, liver, spleen, and CNS.

Inflammatory bowel disease includes Crohn disease, ulcerative colitis, and colitis of indeterminate type. Crohn disease has "skip" lesions, has transmural involvement with formation of granulomas, and tends to form fistulas, abscesses, and sinuses. In contrast ulcerative colitis is confined to the rectum and colon, has inflammation limited to the mucosa and submucosa with crypt abscess, is more likely to have extraintestinal manifestations, and can cause toxic megacolon.

Ischemic bowel disease is the result of decreased blood flow and ischemia of the bowel secondary to atherosclerosis with thrombosis, thromboembolism, or reduced cardiac output from shock. Hemorrhoids are tortuous dilated submucosal veins caused by increased venous pressure. Angiodysplasia is arteriovenous malformation of the intestines. Melanosis coli is a black pigmentation of the colon that is common with laxative abuse. Pseudomembranous colitis is characterized by formation of inflammatory pseudomembranes in the intestine following infection by Clostridium difficile.

Meckel's diverticulum is a congenital small bowel diverticulum that is a remnant of the vitelline duct Colonic diverticulosis is a common condition among the elderly population and features acquired outpouchings of the bowel wall, characterized by herniation of the mucosa and submucosa through the muscularis propna.

Adenomatous colonic polyps are benign neoplasms of the colonic mucosa that have the potential to progress lo colonic adenocarcinoma. Familial adenomatous polyposis is a genetic condition in which patients develop thousands of colonic adenomatous polyps and have a virtually 100% chance of developing colon cancer by age 40 unless the affected colon is resected. Gardner syndrome is a variant of familial adenomatous polyposis with associated osteomas, fibromatosis, and epidermal inclusion cysts. Turcot syndrome is a rare variant of familial adenomatous polyposis associated with CNS gliomas. Hereditary nonpolyposis colorectal cancer has increased risks of colon, endometrial, and ovarian cancers, but it is not associated with multiple adenomatous polyps. Peutz-Jeghers syndrome has multiple hamartomatous polyps with increased risk of cancers of the lung, pancreas, breast, and uterus, but not colon.

Was this article helpful?

0 0
Why Gluten Free

Why Gluten Free

What Is The Gluten Free Diet And What You Need To Know Before You Try It. You may have heard the term gluten free, and you may even have a general idea as to what it means to eat a gluten free diet. Most people believe this type of diet is a curse for those who simply cannot tolerate the protein known as gluten, as they will never be able to eat any food that contains wheat, rye, barley, malts, or triticale.

Get My Free Ebook


Post a comment