4.3 Gastroenterology & Hepatic Disorders

4.3 Gastroenterology & Hepatic Disorders

Gastroesophageal Reflux Disease (GERD) and Peptic Ulcer Disease (PUD)

GERD Management

GERD is characterized by the reflux of stomach contents into the esophagus, causing troublesome symptoms or complications. Typical symptoms include heartburn and regurgitation, while atypical symptoms may manifest as chronic cough, asthma exacerbations, or laryngitis. Alarm symptoms requiring prompt endoscopy include dysphagia, odynophagia, unintentional weight loss, and signs of GI bleeding.

An 8-week course of Proton Pump Inhibitors (PPIs) (e.g., omeprazole, pantoprazole) is the treatment of choice for symptom relief and the healing of erosive esophagitis. PPIs should be administered 30-60 minutes before the first meal of the day to maximize inhibition of active proton pumps. Long-term PPI use is associated with risks including Clostridioides difficile infection, osteoporosis-related fractures, hypomagnesemia, and Vitamin B12 deficiency. H2-Receptor Antagonists (H2RAs) like famotidine are an alternative for mild, non-erosive disease, but tachyphylaxis can develop over time.

PUD and H. pylori Regimens

PUD involves mucosal defects in the stomach or duodenum. The primary causes are NSAID use and Helicobacter pylori infection. Diagnosis of H. pylori requires testing (urea breath test or stool antigen), and patients must hold PPIs for 1-2 weeks prior to testing to avoid false negatives.

Due to increasing macrolide resistance, Bismuth Quadruple Therapy is currently the first-line empiric regimen for H. pylori, administered for 10-14 days. This regimen consists of:

1. Bismuth subsalicylate
2. Metronidazole
3. Tetracycline
4. Proton Pump Inhibitor (PPI) twice daily

Clarithromycin Triple Therapy (PPI + clarithromycin + amoxicillin/metronidazole) should only be used in regions where local clarithromycin resistance is known to be <15% and the patient has no prior macrolide exposure. Concomitant therapy (PPI + clarithromycin + amoxicillin + metronidazole) is an alternative non-bismuth quadruple option.

Inflammatory Bowel Disease (IBD): Crohn's Disease vs. Ulcerative Colitis

IBD represents a group of chronic immune-mediated inflammatory conditions.

• Crohn's Disease (CD): Characterized by transmural inflammation that can affect any part of the GI tract from the mouth to the anus, though it most commonly involves the terminal ileum. Endoscopy often reveals skip lesions and a "cobblestone" appearance. Management relies on targeting the specific location. Budesonide (Entocort EC), which releases in the terminal ileum, is utilized for mild-to-moderate ileal CD. Systemic corticosteroids are used for severe flares. Maintenance therapy often involves immunomodulators (azathioprine, mercaptopurine) and biologic agents, notably anti-TNF alpha inhibitors like infliximab and adalimumab.
• Ulcerative Colitis (UC): Involves superficial mucosal inflammation that is continuous, starting from the rectum and limited exclusively to the colon. Aminosalicylates (5-ASA products like mesalamine) are the cornerstone of therapy for mild-to-moderate UC. Mesalamine suppositories or enemas are highly effective for distal disease (proctitis).

Hepatic Cirrhosis and Complications

Cirrhosis is end-stage liver disease resulting from chronic insult (e.g., alcohol, viral hepatitis, NASH), leading to fibrosis and portal hypertension. The Child-Pugh score assesses severity using total bilirubin, serum albumin, PT/INR, ascites, and hepatic encephalopathy.

Portal Hypertension and Varices

Increased resistance to portal blood flow leads to portal hypertension, driving the development of esophageal varices. Primary and secondary prophylaxis of variceal bleeding is achieved with non-selective beta-blockers (nadolol, propranolol, or carvedilol). These agents reduce portal pressure by decreasing cardiac output (beta-1 blockade) and causing splanchnic vasoconstriction (beta-2 blockade). The dose is titrated to a target heart rate of 55-60 bpm. Acute variceal hemorrhage is a medical emergency managed with fluid resuscitation, EVL (endoscopic variceal ligation), prophylactic ceftriaxone, and continuous IV octreotide (a somatostatin analog that causes splanchnic vasoconstriction).

Ascites

Ascites is the accumulation of fluid within the peritoneal cavity. Management requires sodium restriction (<2,000 mg/day) and diuretic therapy. The optimal diuretic regimen is a combination of spironolactone and furosemide in a 100:40 mg ratio. This specific ratio maintains normokalemia while mobilizing ascitic fluid. For tense ascites, large-volume paracentesis is performed. If >5 liters of fluid are removed, IV albumin (6-8 grams per liter of fluid removed) must be administered to prevent post-paracentesis circulatory dysfunction and hepatorenal syndrome.

Hepatic Encephalopathy (HE)

HE is a reversible neuropsychiatric syndrome caused by the accumulation of gut-derived neurotoxins, primarily ammonia.

• Lactulose is the first-line therapy for both acute treatment and secondary prophylaxis. It converts ammonia (NH3) to ammonium (NH4+), which cannot diffuse back into the blood and is excreted in the feces. The dose is titrated to achieve 2-3 soft bowel movements per day.
• Rifaximin, a non-absorbable broad-spectrum antibiotic, is added as adjunctive therapy to lactulose for patients who experience recurrent HE episodes despite adequate lactulose dosing.

Pain Management in Cirrhosis

Pain management in cirrhotic patients is notoriously challenging due to altered drug metabolism. Acetaminophen (APAP) is generally considered safe and is the analgesic of choice, provided the dose is reduced (typically <2,000 mg/day) and alcohol is strictly avoided. Conversely, Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) must be strictly avoided in all cirrhotic patients due to a high risk of precipitating acute kidney injury, hepatorenal syndrome, and gastrointestinal bleeding.