Small Bowel Flashcards
Most common cause of pediatric diarrhea
Rotavirus
Types of diarrhea
Infectious, malabsorption, osmotic, increased motility, secretory
Ddx of chronic diarrhea
Secretory: carcinoid tumor or VIPoma
Malabsorption/maldigestive/osmotic: bacterial overgrowth, pancreatic insufficiency, mucosal damage, lactose intolerance, celiac dz, laxative abuse, short bowel syndrome
Inflammatory: IBD
Increased motility: IBS
When to workup acute diarrhea
Further workup if patient has a high fever, bloody diarrhea, or diarrhea > 4-5 days
Watery vs. bloody diarrhea organisms
Watery: Vibrio cholera, ETEC, Giardia, C diff, rotavirus, Cryptosporidium
Bloody: EHEC, Salmonella, Shigella, Campylobacter
Campylobacter:
-Hx, Exam, Tx
Hx: most common etiology of bacterial diarrhea; ingestion of contaminated food/water; affects young children and young adults
Exam: Fecal RBCs and WBCs; p/w bloody diarrhea, fever, and no abdominal pain
Tx: erythromycin
C diff
-hx, exam, tx
Hx: a/w recent antibiotic use (especially clinda) and recent hospitalization
-be careful about toxic megacolon
Exam: p/w fever, abdominal pain, systemic toxicity; fecal RBCs and WBCs
-causes colitis; dx w/ toxin in stool; sigmoidoscopy shows pseudomembranes
Tx: PO metronidazole or PO vanc; IV metronidazole if pt can’t tolerate PO
Entamoeba histolytica
-hx, exam, tx
Hx: 2/2 ingestion of contaminated food or water (Trave)
Exam: severe abdominal pain and fever; fecal RBCs and WBCs; endoscopy shows flask-shaped ulcers”
-mimics IBD if chronic
Tx: steroids can cause fatal perforation. DON’T USE STEROIDS; tx w/ metronidazole
E. coli 0157:H7
-Hx, exam, tx
Hx: bloody diarrhea, ingestion of raw meat; lasts 5-10 days
Exam: p/w severe abdominal pain, low-grade fever, vomiting, and bloody diarrhea; fecal RBCs and WBCs
-rule out GI bleed and ischemic colitis; HUR is a potential complication (thrombocytopenia and renal failure)
Tx: avoid antibiotics or antidiarrhea therapy because they increase HUS risk
Salmonella
-hx, exam, tx
Hx: 2/2 ingestion of contaminated poultry or eggs
Exam: p/w prodromal HA, fever, myalgia, and abdominal pain
- Fecal WBCs
- sepsis is a concern as 5-10% of pts become bacteremic; sickle cell pts are prone to osteomyelitis
Tx: oral quinolone or TMP-SM if pts are bacteremic or have sickle cell
Shigella
-Hx, exam, tx
Hx: very contagious, transmitted fecal-oral
Exam: fecal RBCs and WBCs; bloody diarrhea
-can cause severe dehydration and febrile seizures
Tx: TMP-SMX to prevent spread
Intestinal villous atrophy
a/w Celiac disease
Dermatitis herpetiformis
a/w celiac dz
grouped, papulovesicular pruritic skin lesions
symmetrically located on extensor surfaces of elbows, knees, buttocks, and posterior scalp
Frequent, loose, watery stools which are pale, foul-smelling, bukly
a/w abdominal pain, flatus, bloating, weight loss, nutritional deficiencies, and fatigue
Malabsorptive diarrhea
ddx: mucosal (Celiac, Whipples dz, tropical sprue), bile salt deficiency (bacterial overgrowth), pancreatic insufficiency, or short bowel syndrome
Pellagra
Sx: Diarrhea, dementia, dermatitis, death
-high sensitivity to sunlight; ataxia, confusion, insomnia; beefy, red glossitis; dilated cardiomyopathy;
Vitamin B3 (niacin) deficiency 2/2 decreased niacin or tryptophan intake
Lactose intolerance:
-pathophysiology, common populations, hx/PE, Dx, Tx
Pathophysiology: lack of lactose; can occur after gastroenteritis transiently; common in Asian, Native Americans, and Africans
Hx/PE: abdominal bloating, flatulence, cramping, watery diarrhea after milk ingestion
Dx: empiric lactose-free diet that improves symptoms
-Hydrogen breath test reveals increased hydrogen after ingestion of lactose
Tx: avoid dairy products
Carcinoid syndrome vs. carcinoid tumor
Syndrome: after tumor mets to liver
Tumor: presence of carcinoid tumor
What do carcinoid tumors produce?
Serotonin
Why are there no sx before carcinoid tumor metastasizes?
Serotonin undergoes first-pass metabolism in the liver
Carcinoid syndrome
-sx, dx, tx
Flushing, diarrhea
Abdominal cramps, wheezing, right-sided cardiac valvular lesions
Dx: high urine levels of 5-HIAA; CT and In-111 octreotide scans can localize the tumor
Tx: octreotide and surgical resection
Constipation, abdominal distention, mucous stools and abdominal pain that relieved by bowel movements
Irritable bowel syndrome
Partial vs complete SBO
Partial: continued passage of flatus
Complete: no passage of flatus or stool
Causes of small bowel obstruction
Most common: adhesions, hernias
Neoplasms, intussusception, gallstone ileus, stricture, volvulus
Typical symptoms of an SBO
Crampy abdominal pain at 4-5 minute intervals
Vomiting: proximal = early and bilious; distal = late and feculent
Exam: distention
Bowel sounds: high-pitched tinkles and peristaltic rushes
Pt w/ hx of carcinoid tumor (resected) who presents with symmetric, dry, b/l hyperpigmented skin lesions, persistent diarrhea, and complaints that she is not herself anymore (irritable, confused, forgetful). Likely diagnosis?
Pellagra 2/2 carcinoid syndrome recurrence
-Carcinoid tumors produce serotonin which is derived from tryptophan. Tryptophan is also the precursor of niacin, so patients with carcinoid tumors may be using all of their tryptophan for serotonin production and not making enough niacin
Dx of small bowel obstruction
Abxominal films stepladder pattern of dilated small-bowel loops, air fluid levels, and paucity of gas in the colon
Tx of partial and complete SBO
Partial: NPO, NG tube, IVF, correction of electrolyte abnormalities, and Foley to monitor fluid status
-if sx > 3 days, then do ex-lap
Complete: ex-lap
Gallstone ileus
SBO where gallstone erodes through intestinal wall into the lumen of the GI tract and lodges in the ileocecal valve
Obstruction vs. ileus
Obstruction: physical obstruction in the bowel causing backup
Ileus: loss of peristalsis without structural obstruction
Obstruction has hyperactive bowel sounds while ileus has none
X ray differences between ileus and SBO
SBO has air in small bowel, none in colon (distal to the SBO)
Ileus has diffuse air present throughough the GI tract
Tx for ileus
NPO, NG suction, TPN, IVF
2 most common causes of mesenteric ischemia
Thrombotic occlusion: acute thrombosis in the SMA. primary risk = atherosclerosis
Embolism: from heart; risks = a-fib and stasis from a decreased ejection fraction
Intestinal angina
Episodes of pain after eating related to increased blood needs for the gut and inability to get it due to atherosclerosis
Pneumatosis intestinalis
Air within the bowel
In neonates = necrotizing enterocolitis
In adults it can mean mesenteric ischemia
Tx of acute bowel ischemia
Volume resuscitation and antibiotics
Acute arterial thrombosis/embolus: anticoagulation and laparotomy
Venous thrombosis: anticoagulation
Surgical resection of infarcted bowel
