Digestive / GI

When acid beats the mucosa’s defenses, the lining ulcerates — and when an ulcer erodes a vessel, the patient can quietly bleed toward shock.

A scarred liver stops making what the body needs and stops clearing what poisons it — and the pressure backing up behind it creates four complications every nurse must know.

Digestive enzymes switch on inside the pancreas and the gland digests itself — mild and self-limiting in most, but capable of shock, hypocalcemia, and ARDS in the severe form.

Intestinal contents stop moving — blocked by adhesions, hernia, or tumor, or stalled by a paralyzed gut — and fluid pours into the bowel instead of the circulation.

A blocked, inflamed appendix on a clock: obstruction → distention → ischemia → rupture — and the classic trap where the pain suddenly easing means it just burst.

Two lifelong, relapsing immune-driven bowel diseases — ulcerative colitis burns the colon lining continuously from the rectum up; Crohn’s disease bores through the full wall anywhere from mouth to anus. The flare that kills is toxic megacolon.

Stomach contents climb back into the esophagus because the barrier at the bottom fails — often because part of the stomach has slid up through the diaphragm. Heartburn is the nuisance; the twisted hernia and the "heartburn" that is really a heart attack are the emergencies.

Five viruses, one target organ. Two arrive through food and water and burn out; three arrive through blood and can smolder for decades toward cirrhosis and liver cancer.

A gallstone lodges in the cystic duct and a storage sac becomes a pressurized, ischemic, infected one — and if a stone drops into the common bile duct, jaundice, pancreatitis, or septic cholangitis follow.

Most older adults carry small pouches in the sigmoid colon without knowing it; a few of those pouches bleed painlessly, and a few become inflamed — and the teaching on fibre, antibiotics, nuts and surgery has changed more in the last decade than almost anything else in gastroenterology.

A cancer that almost always starts as a polyp and takes years to turn malignant — which is why screening from age 45 prevents it, why the side of the colon changes the symptoms, and why the nurse’s work spans the stool test, the stoma and the chemotherapy chair.

An autoimmune reaction to gluten flattens the villi of the small intestine, so iron, folate, B12, fat and the fat-soluble vitamins are lost — often with anemia or fatigue and no gut symptoms at all. The only treatment is a strict gluten-free diet for life.

The leading cause of antibiotic-associated diarrhea: antibiotics wipe out protective gut bacteria, C. diff spores germinate and release toxins A and B, and the colon becomes inflamed. Isolate on suspicion with gown and gloves, wash hands with soap and water, clean with a sporicidal disinfectant, test only unformed stool, treat with oral vancomycin or fidaxomicin — and watch for toxic megacolon.

Usually a ductal adenocarcinoma of the pancreatic head that stays silent until it has spread. The classic clue is painless jaundice from a blocked bile duct, with weight loss and new diabetes. It is not screened for in average-risk adults, surgery is the only cure, and overall 5-year survival is about 13% (NCI).

A brain dysfunction in liver disease caused by gut-derived toxins, above all ammonia, that the failing liver no longer clears. It ranges from subtle deficits to coma. The nurse hunts for the trigger (bleeding, infection, constipation, dehydration, sedatives), gives lactulose to 2–3 soft stools a day, and keeps a confused patient safe.

Two upper-GI cancers that are usually found late. Esophageal squamous cell carcinoma follows smoking and alcohol; adenocarcinoma follows long-standing reflux and Barrett esophagus. Gastric cancer follows chronic H. pylori infection. Progressive dysphagia, early fullness and weight loss are the clues. After surgery the nurse watches for anastomotic leak and aspiration, supports jejunostomy feeding, and teaches the dumping-syndrome diet and the risk of vitamin B12 deficiency.