Comprehensive Study Guide: IBS, Diverticular Disease, and Hepatic Physiology

Vocabulary flashcards derived from lecture notes covering Irritable Bowel Syndrome, diverticular disorders, liver anatomy and functions, and associated treatment guidelines.

Irritable Bowel Syndrome (IBS) Definition

A clinical syndrome characterized by gut sensitivity and altered motility that can affect any segment of the gastrointestinal tract, causing abdominal pain, cramping, bloating, diarrhea, and constipation.

Pathophysiologic Causes of Irritable Bowel Syndrome

Altered gastrointestinal motility (episodes of slowing and speeding up), luminal irritation, and hormonal changes associated with psychological conditions like anxiety and depression.

Common Triggers of IBS Flare-Ups

Specific foods that cause bloating, psychological or physical stress, and concurrent acute illnesses.

IBS Diagnostic Criteria

Abdominal pain and discomfort lasting at least $12\,weeks$ (non-consecutive) within a year, accompanied by at least two of the following: change in stool frequency or consistency, urgency or feeling of incomplete evacuation, presence of mucus in the stool, and bloating or abdominal distension.

Red Flag Clinical Signs in Suspected IBS

Manifestations that necessitate advanced diagnostic testing, including new onset of symptoms after age $50$, symptoms requiring evaluation to rule out colon cancer, unexplained weight loss, and high fever.

Diagnostic Tests for Evaluating Red Flag Symptoms in IBS

Flexible sigmoidoscopy (to view the rectum and sigmoid colon), full colonoscopy, abdominal CT scan, and stool studies to rule out parasitic infections.

Pharmacological Therapy for IBS-C (Constipation-Predominant)

Lubiprostone (Amitiza), which acts as a gastrointestinal motility enhancer to relieve severe constipation.

Pharmacological Therapy for IBS-D (Diarrhea-Predominant)

Alosetron Hydrochloride (Lotronex), a gastrointestinal motility modifier indicated for severe diarrhea-predominant symptoms.

Short-Term Anti-Diarrheal for IBS Symptom Relief

Loperamide (Imodium), used short-term to decrease stool frequency during diarrhea episodes.

Non-Pharmacological and Lifestyle Interventions for IBS

Fiber supplementation, probiotic use, dietary adjustments (eliminating dairy and caffeine, eating smaller meals), stress management, counseling, regular exercise, yoga, massage, deep breathing, hypnosis, acupuncture, and herbal remedies.

Major Functions of the Liver

Production of bile and cholesterol, conversion of excess glucose into glycogen for storage, filtration and detoxification of blood, regulation of blood clotting, and synthesis/excretion of bilirubin.

Anatomical Structure of the Human Liver

A $3\,pound$ organ divided into $4$ lobes that are separated by the falciform ligament.

Definition and Characteristics of Diverticulosis

The presence of small, marble-sized outpouchings measuring less than $10\,mm$ that protrude through naturally weak areas of the colon wall, occurring in $50\%$ of individuals over age $60$.

Predominant Anatomical Locations for Diverticular Outpouchings

Primarily located in the descending and sigmoid colon in Western populations, but predominantly in the ascending colon in Asian populations.

Pathophysiology and Definition of Diverticulitis

An acute inflammatory condition affecting pre-existing intestinal diverticula, often triggered by micro-perforation or blockage within the outpouchings.

Key Risk Factors for Diverticular Disease

Age over $60$, low-fiber diet leading to hard stools, physical inactivity, family history, diabetes mellitus, smoking, and obesity.

Clinical Signs and Symptoms of Acute Diverticulitis

Severe left lower quadrant (LLQ) abdominal pain ($6\text{ to }10$ out of $10$ on severity scale) that is relieved by bowel movements and worsened by eating, accompanied by fever, nausea, vomiting, a palpable abdominal mass, bloating, and constipation.

Differential Diagnoses for Diverticulitis Symptoms

Colon cancer, inflammatory bowel disease (IBD), urinary tract infection (UTI), kidney stones, and gynecological pathologies such as ovarian cysts, ectopic pregnancy, pelvic inflammatory disease (PID), and endometriosis.

Definition and Clinical Features of Meckel's Diverticulum

A congenital birth defect present in $2\%$ of the population involving a remnant of the yolk stalk that forms a sac in the lower ileum of the small intestine.

Diagnostic Imaging Test of Choice for Acute Diverticulitis

Computed Tomography (CT) of the abdomen.

Key Diagnostic Precaution in Acute Diverticulitis

Colonoscopy must be avoided during acute diverticulitis because pressure from scope insertion risks perforating the acutely inflamed bowel wall.

Outpatient Treatment Protocol for Mild Diverticulitis

Prescribed for uncomplicated cases in patients able to tolerate oral liquids, consisting of clear liquid diet advancement and a $7\text{ to }10\,day$ course of oral antibiotics.

Inpatient Treatment Protocol for Severe Diverticulitis

Required for significant inflammation, inability to tolerate liquids, or patients over age $85$; includes complete bowel rest, IV antibiotics, vital sign monitoring, and transitioning to oral antibiotics for $7\text{ to }10\,days$ following clinical improvement and diet advancement.

Surgical Indication and Procedure: Bowel Resection

Surgical removal of inflamed or damaged segments of the bowel, performed depending upon the severity and extent of inflammation.

Lifestyle and Preventive Recommendations for Diverticular Health

Consuming $20\text{ to }30\,g/day$ of dietary fiber, performing $30\,min/day$ of daily exercise (including weights), maintaining adequate daily water intake, and promptly responding to bowel urges to prevent stool hardening and wall perforation.