Small Intestine: Medical Abdominal Pain

Acute Viral Gastroenteritis

Most Common Organisms

  • Norovirus #1 – From Contaminated Food/Water or Person-to-Person Spread
  • Rotavirus
  • Enteric Adenovirus
  • Astrovirus

Presentation

  • Diarrhea (89%)
  • Nausea (93%)
  • Vomiting (81%)
  • Abdominal Pain (76%)
  • Fever (50%)
  • Weight Loss
  • Fatigue
  • Dehydration

Diagnosis

  • Clinical – Characteristic History of Diarrheal Disease (≥ 3 Times Per Day with Rapid Onset for < 1-2 Weeks) Accompanied by Other GI Symptoms

Treatment

  • Supportive Care (Fluid Rehydration & Unrestricted Nutrition)
  • ABX Generally Not Recommended

Irritable Bowel Syndrome (IBS)

Basics

  • Definition: Chronic Abdominal Pain & Altered Bowel Habits without any Organic Cause
  • The Most Commonly Diagnosed GI Condition
  • Pathophysiology Multifactorial & Uncertain

Subtypes

  • IBS-C (Constipation): > 25% of Stools Hard (Bristol Type 1 or 2)
  • IBS-D (Diarrhea): > 25% of Stools Loose (Bristol Type 6 or 7)
  • IBS-M (Mixed): Both C & D
  • IBS-U (Unsubtyped): Neither C, D or M
  • IBS-A (Alternating): Alternates Between C & D

Diagnosis (Rome IV Criteria)

  • Recurrent Abdominal Pain ≥ 1 Day/Week
    • *Not Abdominal “Discomfort” as Was in Rome III Criteria
  • Lasting for ≥ 3 Months
  • At Least 2 Of:
    • Pain Related to Defecation
    • Change in Stool Frequency
    • Change in Stool Form

Treatment

  • Initial Tx: Lifestyle & Dietary Modifications
    • Diet – Avoid Gas-Producing Foods & Low FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides & Polyols)
    • May Have Concurrent Celiac Disease or Lactose Intolerance Requiring Gluten/Dairy Avoidance
    • Psychological Therapy May Benefit Some Patients
  • If Fails or Moderate-Severe Sx: Add Pharmacologic Tx (Laxatives or Antidiarrheals)

Celiac Disease (Celiac Sprue/Gluten-Sensitive Enteropathy)

Basics

  • Definition: Small Bowel Disorder Upon Exposure to Dietary Gluten with Relief After Withdrawal of Gluten from Diet
  • Primarily Occurs in Whites of Northern European Ancestry
  • Classically a Disease of Infants After Introduction of Gluten into the Diet
    • Now Presenting Later, Often in Adults

Presentation

  • Primary Sx:
    • Abdominal Pain
    • Diarrhea
    • Steatorrhea
    • Flatulence
  • Other Sx:
    • Nutrient & Vitamin Deficiencies
    • Iron Deficiency Anemia
    • Neuropsychiatric Disorders
    • Arthritis
  • Associated Conditions:
    • Dermatitis Herpetiformis
    • Type 1 Diabetes
    • Autoimmune Thyroiditis
    • Down Syndrome
    • GERD
    • Inflammatory Bowel Disease
    • Selective IgA Deficiency

Diagnosis

  • Serology: Anti-Tissue Transglutaminase IgA Antibody (Best)
    • Other Antibodies: Anti-Endomysial Ab or Anti-Gliadin Ab
    • Indicative but Need Bx for Diagnosis
  • Endoscopic Small Bowel Bx: Atrophic/Flattened Villi, Crypt Cell Hyperplasia & Mucosal Inflammation

Treatment

  • Gluten-Free Diet (Wheat, Rye & Barley)
  • May Have Concurrent Lactose Intolerance Requiring Dairy Avoidance

Celiac Disease Histology – Flattened Villi & Crypt Cell Hyperplasia 1

Lactose Intolerance

Definitions

  • Lactase Deficiency – Deficiency of Lactase (Brush Border Enzyme to Allow Absorption of Lactose)
    • Excess Lactose in Colon Causes Fermentation by Bacteria with Production of Hydrogen Gas
  • Lactose Intolerance – Clinical Syndrome Where Lactose Ingestion Cases Symptoms
    • May or May Not Be Associated with Lactase Deficiency

Presentation

  • Symptoms Develop After Lactose Ingestion
  • Symptoms:
    • Abdominal Pain
    • Bloating
    • Flatulence
    • Nausea
    • Diarrhea

Diagnosis

  • Lactose-Tolerance Test
    • Provocative Oral Lactose Load Given & Monitoring of Symptoms
    • Diagnoses Lactose Intolerance
  • Lactose Hydrogen Breath Test
    • Diagnoses Lactose Malabsorption

Treatment

  • Restrict Lactose in Diet (Dairy)
  • May Consider Lactase Enzyme Replacement

References

  1. Sayar I, Demirtas L, Gurbuzel M, Isik A, Peker K, Gulhan B. Familial multiple lipomas coexisting with celiac disease: a case report. J Med Case Rep. 2014 Sep 16;8:309. (License: CC BY-4.0)