5 IBS, Constipation, Diarrhea Flashcards
Which features are NOT associated with IBS?
Iron deficiency anemia
Weight loss
Severe or progressively worsening symptoms
All should prompt further investigation and referral to gastroenterologist
What is the definition of IBS?
FUNCTIONAL bowel disorder (absence of biochemical cause) characterized by RECURRENT ABDOMINAL PAIN AND ALTERED BOWEL HABITS (need both elements)
What are the different subclassifications of IBS?
IBS-C (Constipation predominant)
IBS-D (Diarrhea predominant)
IBS-M (Mixed)
IBS-U (Unclassified)
IBS typically affects patients ______ y.o. and ______
20-39yo and F>M
Etiology of IBS is likely…
Multifactorial
Physiological - abnormal motility, visceral hypersensitivity
Psychosocial - early life stressors (abuse), anxiety, depression, phobias
Environmental - diet, post-infectious (gastroenteritis), gut microbiome
Main clinical presentation of IBS
Chronic/Recurrent abdominal pain/discomfort
• Cramping, diffuse (lower abdomen)
• Variable intensity
• Periodic exacerbation
Altered bowel habits
• Constipation vs. Diarrhea vs. Mixed vs. Unclassified
If IBS presents with GI symptoms as well, you might see…
Dyspepsia
Atypical CP
Vomiting (rare)
Extra-intestinal Sx of IBS
Sexual dysfunction Dysmenorrhea Irritative voiding symptoms Fibromyalgia symptoms Somatic or psychological complaints
What are the RED FLAG SYMPTOMS for IBS?
KNOW THESE*
Symptom onset after age 50 Severe or progressively worsening symptoms Nocturnal diarrhea Fevers/vomiting Unexplained weight loss Melena, hematochezia, occult blood Personal or FH of colon cancer, IBD, or celiac disease Unexplained iron deficiency anemia
Why do you need to do a perianal/DRE when working up IBS?
To rule out Crohn’s or fissure
More common DDx for IBS
Lactose intolerance Celiac disease Drug induced GI infection IBD Colon cancer
Less common DDx for IBS
Colitis Pancreatic insufficiency Small intestinal bacterial overgrowth Diabetes/thyroid disease Psychiatric disease
What is the diagnostic criteria for IBS?
Rome IV criteria
Recurrent abdominal pain on average at least ONE DAY PER WEEK in the LAST THREE MONTHS, and with two or more of the following:
• Related to defecation
• Associated with a change in stool frequency
• Associated with a change in stool form (appearance)
Most IBS-C patients have Bristol stool types _______, while IBS-D patients have types ______
IBS-C = Bristol types 1 and 2
IBS-D = Bristol types 6 and 7
How to diagnose IBS
If typical hx and no alarm features - laboratory, radiographic, and endoscopic tests not routine
+/- limited screening studies as clinically appropriate (ie CBC, CMP, TSH, ESR/CRP, Celiac serological, stool studies)
If atypical hx, alarm features, or refractory to tx - lab/stool studies, cross-sectional/small bowel imaging, and endoscopy/colonoscopy with biopsies
Goal of IBS treatment is…
To relieve symptoms and improve QOL
Achieved through dietary/lifestyle mods, psychosocial support, and pharmacological therapy
Therapeutic clinician-patient relation is important (continuity of care)
What dietary/lifestyle mods should be suggested to IBS patients?
Food diary/symptom log helpful to ID triggers
Add dietary fiber (20-35g/day) - start low and increase slowly to reduce bloating/gas
FODMAP diet
+/- probiotics
Exercise
What is the FODMAP diet?
Focuses on eliminating foods that contain sugars and fibers that cause pain and bloating
Eliminate x 4-8 weeks then gradually reintroduce 1-2 foods at a time and assess tolerance
Trained dietitian helpful to avoid unnecessary dietary over restriction
May not be appropriate for everyone
What type of psychosocial support is necessary for IBS patients?
Cognitive-behavioral therapy
Relaxation/stress management
+/- behavioral health referral
What drugs can be used by IBS patients to alleviate abdominal pain?
Levsin (Hyoscyamine) and Bentyl (Dicyclomine)
Both are antispasmodic
CAUTION - anticholinergic effects**
What drugs can be used to relieve Sx in IBS-C?
Psyllium fiber
Miralax (polyethylene glycol)
Amitiza (Lubiprostone)
Linzess (Linaclotide)
Trulance (Plecanatide)
What drugs can be used to relieve Sx in IBS-D?
Imodium (Loperamide)
Rifaximin (abx that just works in the gut)
Alosteron (women only)
Viberzi (Eluxadoline)
What drugs are used off-label in IBS for their psychosocial benefit?
TCAs
Caution - AEs **
Name three broad etiologies of IBS
Physiological
Psychosocial
Environmental
NO SINGLE UNIFYING ETIOLOGY
What meds can exacerbate constipation?
Antipsychotics Anticholinergics Iron Antacids (esp Calcium, aluminum) Opioids CCBs
Most common digestive complaint in general population
Constipation
But most do not have serious disease
Risk factors for constipation
Improper diet and inadequate fluid intake
Sedentary lifestyle
Polypharmacy
Age
What is Colonic Inertia?
Constipation caused by slow transit —> bowel movement only once every 7-10 days
Defecation/obstructive disorders that can cause constipation
Pelvic floor dysfunction Anorectal disease Rectal prolapse Rectocele Colon cancer Polyp Stricture/stenosis Fecal impaction/obstruction
Metabolic/systemic diseases that can cause constipation
Hypercalcemia Hyperparathyroidism Hypothyroidism DM Pregnancy Hirschprung MS Parkinson Spinal cord injuries
Key history questions to ask when working up constipation
Acute or chronic Normal bowel pattern Frequency, consistency of stool Laxative use**** Need for digital evacuation**** Previous colonoscopy**** Red flag symptoms/alarm features**** Any secondary/contributing cases (reconcile meds, review PMH)
What do we mean by constipation?
<3 spontaneous BM/week
Lumpy or hard stools
Straining
Manuel maneuvers to facilitate defection (digital evacuation, support of the pelvic floor)
Sensation or anorectal obstruction/blockage
Sense of imcomplete evacuation
Constipation may also present with these GI symptoms…
Abdominal pain and bloating
Pain on defection
Rectal bleeding
TENESMUS
Red flag symptoms for constipation
Acute onset Symptom onset after age 50 Fevers/vomiting Unexplained weight loss Melena, hematochezia, occult blood Personal or FH of colon cancer, IBD, celiac disease Iron deficiency anemia
PE components for constipation
(Usually benign)
Abdominal exam to evaluate for distention, masses
DRE (evaluate for fissures, hemorrhoids, tenderness, masses, stool, anal stricture, anal sphincter tone, perineal descent, dyssynergic defection)
Pelvic exam to evaluate for rectocele
What is dyssynergic defecation?
Do DRE and ask patient to valsalva —> drowns your finger in (🤮)
What diagnostics do you need to do for constipation?
Limited lab eval necessary (+/- CBC, CMP, TSH)
Alarm features —> further eval
• Imaging studies
• Colonoscopy or flex sig to ID lesions that narrow or occlude the bowel
How to evaluate refractory constipation patients
Colonic transit (radiopaque marker) study - evaluates rate of residue moving through colon
Defecography - assesses for anatomical/functional changes
Anorectal manometry - measures anal sphincter pressure/function
Dietary/lifestyle mods for constipation
Increase fluid/fiber intake
Increase activity/exercise
Bowel habit training
Biofeedback helpful with defecatory dysfunction
What medication therapies are available for constipation?
Fiber supplements
Stool softeners
Osmotic and stimulant laxatives
Ex agents
Adverse effects of fiber supplements
Flatulence
Bloating
Distention
Adverse effects of osmotic laxatives
GI discomfort/bloating
CAUTION - Mg-containing laxatives and hypermagnesemia in patients with RENAL INSUFFICIENCY
Adverse effects of stool softeners
GI cramping
Adverse effects of stimulant laxatives
GI cramping
Rarely lyte disturbances
Melanosis coli (benign)
Complications of constipation
Hemorrhoids/anal fissures
Fluid and electrolyte abnormalities from laxative abuse
Fecal impaction —> bowel obstruction
Who are at higher risk of fecal impaction?
Patients with dementia, neurologic disease, immobile, or on hypomotility meds
Present with N/V, abdominal pain, distention, paradoxical “diarrhea” (only liquid passing)
What is the most likely cause of acute diarrhea?
Viral infection (esp Norovirus)
What is the definition of diarrhea?
Passage of ≥ 3 unformed stools/day
Diarrhea is considered acute if duration is…
<14 days
Diarrhea is considered persistent if duration is …
14-30 days
Diarrhea is considered chronic if duration is …
> 30 days
Most common cause of acute diarrhea?
Infectious***
• Viral*
• Bacterial
• Protozoal
Non-infectious causes of acute diarrhea
Meds Fecal impaction Food intolerance Radiation/ischemic colitis Appendicitis Diverticulitis Intussusception Emotional stress IBD Celiac disease
Red flag symptoms for diarrhea
Fever Unexplained weight loss Melena, hematochezia, occult blood Persistent/progressive/nocturnal symptoms Immunocompromised Personal or FH of colon cancer, IBD, celiac Iron deficiency anemia SIGNS OF VOLUME DEPLETION
Acute diarrhea is considered noninflammatory if…
Watery and nonbloody, +/- N/V
Mild diffuse abdominal cramps, bloating/flatulence
+/- low grade fever
Possible etiologies of noninflammatory acute diarrhea
Viral: Norovirus, rotavirus
Bacterial: Vibrio cholera, Clostridium perfringens, Staph aureus, Bacillus cereus
Protozoal: Giardia, Cryptosporidium, Cyclospora
Acute diarrhea is considered inflammatory if…
Fever
Bloody
Severe abdominal pain
Possible etiologies of inflammatory acute diarrhea
Viral: CMV
Bacterial: Salmonella, Campylobacter, Shigella, Enterohemorrhagic E. coli O157:H7, C. difficile, Vibrio parahemolyticus, Yersinia
Protozoal: entamoeba histolytica
The focus for your PE in diarrhea cases should be…
Volume status and complications
Diagnostics not routinely warranted for most patients
When should acute diarrhea —> prompt evaluation?
Signs of inflammatory diarrhea (Fever ≥ 101.3, leukocytosis, bloody diarrhea, severe abdominal pain)
Intractable vomiting
Profuse watery diarrhea and dehydration
AKI/electrolyte abnormalities
Elderly or nursing home residents
Immunocompromised
Hospital-acquired diarrhea, exposure to abx
Treatment of acute diarrhea is usually…
Supportive care and symptomatic relief • Oral rehydration therapy • Trial of lactose free diet • Probiotics? • +/- antidiarrhea agents
What adverse effect do you need to warn patients about when prescribing bismuth subsalicylate?
Black stool 💩💩💩💩
Older children/adults with acute diarrhea, with hx of prepared foods, sick contacts (CRUISE ships, camps, healthcare facilities, schools, daycare)
Norovirus
Viral diarrhea typically affecting kids 6 months to 2 years, with hx of sick contacts
Rotavirus
Rice-water diarrhea, travel hx to area with unsanitary conditions
Vibrio cholerae
Supportive case, MAYBE doxy, macrolide, tetracycline, FLQ
C. perfringens, S. aureus, and B. cereus cause diarrhea primarily via…
Enterotoxins, typically food borne
Inadequately heated/reheated meats, poultry, gravy, home-canned goods
Clostridium perfringens
Food borne diarrhea - creamy foods, egg/potato salad, dairy, processed meat
Illness within hours of exposure
Staphylococcus aureus
Food borne diarrhea: Grains (esp rice)
Illness within hours of exposure
Bacillus cereus
Camping, lakes, streams, ponds
Giardia lamblia
Treat with metronidazole
Diarrhea from cryptosporidium is associated with …
Recreational water outbreaks, daycares
Self-limited except in AIDS patients
Cyclospora is associated with
Imported foods (fresh fruits, veggies)
Treat with TMP-SMX
Inflammatory bacterial diarrhea associated with poultry and lifestock
Salmonella
Inflammatory bacterial diarrhea that can be linked to Guillan-Barre syndrome
Campylobacter jejuni
Undercooked poultry, unpasteurized milk
“Classic dysentery” etiology
Shigella - fecal contamination of food/water (daycares, crowded living)
Severe afebrile bloody diarrhea
Enterohemorrhagic E. coli (O157:H7) - shiga toxin producing
Associated with undercooked ground beef or unpasteurized products
Why don’t we give antidiarrheals or abx to patients with O157:H7 E. coli?
Risk of HUS
Recent hospitalization or abx use —> acute inflammatory diarrhea
C. diff
Discontinue inciting abx, give vancomycin, fidaxomicin, or metronidazole
Inflammatory diarrhea associated with raw seafood/shellfish
Vibrio parahemolyticus
Which inflammatory diarrhea etiology mimics appendicitis?
Yersinia enterocolitica - from undercooked pork, unpasteurized milk, or Fe ally contaminated water
