Diarrhea – Chronic, with Weight Loss

Differential Diagnosis

• Allergic enteritis: Typically cow's milk or soy in infants
• Inflammatory bowel disease (IBD)
• Cystic fibrosis (CF)
  –Chronic diarrhea may be the only sign
  –90% have pancreatic insufficiency (PI)
• Celiac disease (CD): Gluten sensitivity, increased incidence in selective IgA deficiency, DM, and Down syndrome
• Immune deficiency (e.g., hypogammaglobulinemia)
• Sucrase-isomaltase deficiency: Autosomal recessive, symptoms with starting sucrose or glucose polymer-containing diet
• Microvillus inclusion disease: Most common cause of persistent diarrhea in the neonatal period
• Schwachman-Diamond syndrome
  –Pancreatic insufficiency, neutropenia, short stature, skeletal abnormalities
• Johannson-Blizzard syndrome
  –Pancreatic insufficiency, scalp defects, agenesis of nasal cartilage, deafness, imperforate anus
• Whipple disease:
  –Tropheryma whippelii (actinomycete)
  –Diagnosed mainly in adults
  –Weight loss, diarrhea, and arthropathy
• Tropical sprue: Common in developing countries; folate deficiency and diarrhea
• Neural crest tumors: Pheochromocytoma, VIPoma, Zollinger-Ellison syndrome, carcinoid tumors
• Mastocytoma
• Neuroblastoma
• Abetalipoproteinemia
• Giardiasis, Strongyloides, coccidia
• AIDS
• Acrodermatitis enteropathica: Zinc deficiency, acral perioral and perianal rashes, consider underlying cystic fibrosis
• Mutational defects in ion transport proteins
  –Chloride-losing diarrhea: Rare, ileal chloride transport defect, maternal polyhydramnios
  –Congenital sodium diarrhea
• Tufting enteropathy (epithelial dysplasia)
• Enterokinase deficiency

Workup and Diagnosis

• History and physical exam
  –Diet history and nutritional assessment, onset, frequency, and consistency, history of foreign travel
  –Associated symptoms: Vomiting, irritability, and rashes (dermatitis herpetiformis) with CD; frequent infections in CF and Schwachman-Diamond; digital clubbing in CF, CD, and IBD
  –Hypertension, tachycardia, anxiety, flushing, and sweating with pheochromocytoma; peptic ulcers with Zollinger-Ellison; wheezing, abdominal pain, flushing with carcinoid tumors; pruritus, flushing, and apnea with mastocytoma

• Stool examination: Oily, bulky, and foul-smelling with fat malabsorption; massive watery stools with secretory diarrhea; blood and mucus seen with colitis; stool for ova and parasites or antigen test for Giardia; WBC, eosinophils in allergic disease; occult blood test, stool pH, electrolytes, osmolarity, reducing substances
• PI proven by 72-hour fecal fat, stool elastase, secretin stimulation test, fat-soluble vitamin deficiency (ADEK)
• CBC, ESR, electrolytes, LFT, albumin (low in CD or IBD)
• Sucrose breath test for sucrase-isomaltase deficiency
• Sweat test to rule out CF
• Endoscopic biopsy: CD, IBD, Whipple diagnosis, microvillus inclusion (abetalipoproteinemia)
• Hormonal assay: Gastrin, vasocative intestinal peptide
• Anti-tissue transglutaminase IgA antibodies for CD

Treatment

• Correct malnourished states
• IBD: Anti-inflammatories (e.g., steroids, 6MP, 5ASA)
• CD: Lifelong gluten-free diet
• CF: Pancreatic enzyme and nutritional supplements including fat-soluble vitamins (ADEK)
• Allergy: Food antigen avoidance
• Sucrase-isomaltase deficiency: “Sucraid” enzyme
• Neural crest tumors: Surgical resections
• VIPoma: Somatostatin
• Gastrinoma: Proton pump inhibitors
• Whipple disease: Trimethoprim-sulfamethoxazole
• Abetalipoprotenemia: No specific treatment
  –Supplements of fat-soluble vitamins and MCT oil
• Acrodermatitis enteropathica: Zinc supplements
• Giardiasis: Metronidazole or nitazoxamide
• Hyperalimentation: Parenteral nutrition may be needed for familial enteropathies