Gastrointestinal Disorders: Bowel Obstruction, Colorectal Cancer, Crohn's, Ulcerative Colitis, Cirrhosis, Pancreatitis, Gallstones, GERD, Gastritis

Bowel obstruction

Partial or complete blockage of the small or large intestinal lumen which impairs movement of intestinal contents.

Types of bowel obstruction

Mechanical and paralytic (functional/ileus).

Causes of mechanical bowel obstruction

Adhesions (intestines stick/mesh together), intussusception (intestine telescopes into itself), volvulus (twisting of intestines), incarcerated inguinal hernia (circulation cut off)

Cause of paralytic bowel obstruction

Loss of peristalsis due to anesthesia, surgery, electrolyte imbalance.

Symptoms of mechanical bowel obstruction

Increased/high-pitched bowel sounds, abdominal pain, colicky pain, nausea, vomiting.

Symptoms of paralytic obstruction

Absence of bowel sounds, no peristalsis.

Diagnosis of bowel obstruction

History and physical exam (H&P), abdominal X-ray, CT, ultrasound.

Treatment of bowel obstruction

NG tube decompression, surgical intervention if needed, correction of fluid and electrolyte imbalances.

Colorectal cancer

Cancer of the colon or rectum; 2nd leading cause of cancer death in the U.S.

Precursors and risk factors for colorectal cancer

Adenomatous polyps, age, family history, high-fat/low-fiber diet, ulcerative colitis.

Screening guidelines for colorectal cancer

Age 40: Digital rectal exam; Age 50: Fecal occult blood test yearly; Sigmoidoscopy every 5 years; Barium enema every 5 years OR colonoscopy every 10 years; High risk: Begin earlier; Positive screening → colonoscopy.

Clinical manifestations of colorectal cancer

Occult (hidden) blood in stool; most symptoms appear later in disease.

Type of inflammation in Crohn's disease

Granulomatous inflammation, primarily submucosal.

Lesion characteristics for Crohn's disease

Skip lesions, cobblestone appearance.

Areas affected by Crohn's disease

Mainly ileum → colon.

Common symptoms of Crohn's disease

Diarrhea, weight loss; strictures, fistulas, abscesses common.

Gold standard for Crohn's disease and ulcerative colitis diagnosis

Colonoscopy/sigmoidoscopy.

Type of inflammation in ulcerative colitis

Ulcerative, exudative, limited to mucosa.

Lesion pattern in ulcerative colitis

Continuous lesions starting in rectum → left colon.

Common symptoms of ulcerative colitis

Diarrhea, rectal bleeding.

Cancer risk in ulcerative colitis

Increased.

Cirrhosis definition

End-stage liver disease with loss of functional liver tissue.

Main causes of cirrhosis

Alcohol, hepatitis, drug/chemical toxicity.

Symptoms of cirrhosis

Often asymptomatic until late; weight loss, anorexia, weakness, diarrhea, hepatomegaly, jaundice, portal hypertension.

Pancreatitis

inflammation of the pancreas

Cause of acute pancreatitis

Premature activation of pancreatic enzymes → autodigestion.

Symptoms of acute pancreatitis

Severe abdominal pain, fever, tachycardia, hypotension, abdominal distention, elevated CRP.

Complications of acute pancreatitis

Fluid collection, infection.

Cause of chronic pancreatitis

Irreversible destruction from alcohol abuse.

Symptoms of chronic pancreatitis

Persistent epigastric/LUQ pain worse with eating or drinking, anorexia, N/V, constipation, flatulence.

Treatment for pancreatitis

NPO, low-fat diet, treat diabetes, pain meds, stop alcohol, parenteral nutrition, surgery if needed.

Cholecystitis

Acute or chronic inflammation of the gallbladder, usually from obstruction by gallstones.

Acute symptoms of cholecystitis

RUQ/epigastric pain, fever, anorexia, N/V, ↑ WBC, ↑ liver enzymes, ↑ bilirubin.

Chronic symptoms of cholecystitis

Vague, fatty food intolerance, belching, GI discomfort.

Cholelithiasis

Gallstones (cholesterol or bilirubin).

Risk factors for cholelithiasis

Abnormal bile composition, bile stasis.

Symptoms of cholelithiasis

Often asymptomatic until obstruction → jaundice, biliary colic.

Portal hypertension definition

Increased resistance to blood flow in the portal venous system.

Complications of portal hypertension

Ascites, splenomegaly, esophageal varices, hepatic encephalopathy (AMS from toxins).

GERD

Backflow of gastric contents into the esophagus due to a weak lower esophageal sphincter (LES), causing heartburn.

Pathophysiology of GERD

Weak/incompetent LES → acidic gastric contents reflux into esophagus → inflammation; decreased salivation reduces acid clearance.

Triggers of GERD

Happens after eating; triggered by spicy foods, fatty foods, caffeine, alcohol.

Risk Factors of GERD

Weak LES, obesity, pregnancy, smoking, alcohol, hiatal hernia.

Complications of GERD

Esophagitis, strictures, Barrett's esophagus.

Gastritis

Inflammation of the gastric mucosa (stomach lining).

Causes of Acute Gastritis

Alcohol, NSAIDs, stress, toxins, infections.

Symptoms of Acute Gastritis

Epigastric pain, nausea/vomiting, hematemesis.

Treatment for Acute Gastritis

Remove the causative agent, supportive care.

Causes of Chronic Gastritis

H. pylori infection, autoimmune conditions, reflux of bile/alkaline substances.

Symptoms of Chronic Gastritis

Vague epigastric pain, anorexia, N/V.

Treatment for Chronic Gastritis

Antibiotics for H. pylori, acid-suppressing drugs.

Protective Factors of Gastric Mucosal Barrier

Tight epithelial junctions, thick mucus layer, bicarbonate secretion, prostaglandins (increase mucus and blood flow), rapid cell regeneration.

Aggressive Factors of Gastric Mucosal Barrier

Acid, pepsin, NSAIDs, alcohol, H. pylori, bile reflux, smoking, coffee, stress.