GI Week 4

What is the chart called that describes stool consistency?

Bristol stool chart

What is the fundamental process of diarrhea?

Incomplete absorption of water from intestinal luminal contests

What is the clinical hallmark of osmotic diarrhea?

Stops with fasting. Unabsorbed particles brings in water

What is the clinical hallmark of secretory diarrhea?

Diarrhea continues despite fasting

What type of diarrhea do antacids and nutritional supplements cause?

Osmotic diarrhea

What are the characteristics of inflammatory diarrhea if the inflamed part is the small bowel?

Large volume, may be associated to steatorrhea, non booody, associated with pain and cramps

What is the characteristics of inflammatory diarrhea if the inflammation is in the colon?

Smaller volume, associated with blood and mucous, accompanied by tenesmus, fever and abdominal pain

What is incontinence?

Involuntary release of rectal contents

How can chemotherapy affect the GI?

Causes intestinal or colonic damage

What causes maldigestion?

Pancreatic insufficiency and bile salt deficiency

What causes malabsorption?

Short bowel disease, celiac, whipples disease, giardiasis, and genetic syndromes

What is a lymphoma?

Primarily occur in the stomach and small bowel, present with diarrhea, weight loss and less commonly small bowel obstruction

What is lymphangiectasia?

Impaired small intestine lymph drainage associated with dilated intestinal lymphatic channels

What causes osmotic diarrhea?

Osmolor load -sugar free products (lactulose,sorbitol), high sugar content, lactose intolerance, antibiotics, antacids

Malabsorption (celiac, bacterial overgrowth, IBD, pancreatic insuffciency)

What is IBD?

Chronic inflammatory disease of the GI tract that encompasses two distinct entities: crohns disease and ulcerative colitis

What subtype is not usually considered under IBD?

Microscopic colitis, lymphocytic and collagenous colitis

What is the incidence of IBD?

Usually diagnosed in 2nd and 3rd decade of life, more prominent in developed nations and northern latitude. Canada has one of the highest incidences , 825/100,000

Why do patients get IBD?

Cause is mostly unknown but is thought to be contributed by genetics and environmental triggers

Where does UC usually affect?

Only the colon

Where does CD affect?

Anywhere from mouth to anus, but more commonly in the terminal ileum and colon

How does smoking affect CD and UC?

Increases risk in CD but can lower risk in UC. Carbon monoxide may have a anti inflammatory affect and nicotine a immunosuppressant

What IBD condition has associated deeper ulcers?

Crohns

How deep does UC ulcers typically go?

Mucosa and submucosa

Does UC or CD have a higher cancer risk?

UC

What IBD condition has granulomas connected?

CD

What is the disease behaviour of UC?

Typically bloody diarrhea with urgency and tenesmus. Can present with constipation when there is proctitis. Frequently small volume and watery as well. Weight loss is less common and fever only present in severe disease

Continuous distribution

What is the disease behavior in CD?

Highly variable. Inflammatory, fibrostenotic, and penetrating . Tenesmus uncommon

Patchy distribution

What are some extra intestinal manifestations of IBD?

Skin disorders like erythema nodosum (painful red bumps typically on shins), pyoderma gangrenosum (large deep open sores)

Joint disorders -peripheral arthritis, sacroilitis, ankllosing spondylitis

Ocular disorders

Hepatobiliary (gall stones)

Renal

What are the goals of therapy for IBD?

Induce remission, maintain remission, improve quality of life, minimize drug related side effects, mucosal healing, nutrition

Best time to treat is early on to reduce damage

What is the treatment pyramid of IBD?

5-ASA, corticosteroids, immunomodulators, biologics and then surgery is last

What are 5-aminosalicylates used for?

In UC they are used to induct and maintain remission, used both orally and topically. In CD they are not effective in small bowel disease but can be used in isolated colonic

When are corticosteroids used in IBd?

In moderate to severe disease, not used for maintainence. There are multiple side effects

What is azathioprine/6-MP used for?

Maintence of remission in CD and UC. Common side effects. Important to monitor WBC and LE, not used for induction because it can take up to 10 weeks to effect onset

What is methotrexate used for?

Used for maintenance of remission in CD. 25 mg once weekly for induction and 15 mg once weekly for maintenance. Multiple side efffeys (teratogenic), takes up to 10 weeks to effect so not good for induction

When is surgery indicated in IBD?

When there are complications such as perforation, toxic megacolon, and dysplasia/cancer or when medical refractory disease (does not improve)

What is ischemic colitis?

Condition that results when blood flow to the colon is reduced to a level insufficient to maintain cellular metabolic function. Inadequate Perfusion caused by low flow state, hypovelemia, blood loss and dehydration (no blocking or obstructing)Or can be caused by arterial or venous ischemia

Where are common locations for ischemia?

Splenic flexyre (Griffith point) and Sudaks point (signoidrectal flexure)

What are risk factors for ischemic colitis?

Frailty, vascular disease, age smoking, diabetes, hypertension, recent surgery

What are typical outcomes of ischemic colitis?

70% are self limited, 10% perforate, 5% stricture and 15% goes to chronic colitis

What is the presentation of ischemic colitis?

Left sided abdominal pain and tenderness, rectal bleeding and bloody diarrhea, infectious diarrhea

What is the gold standard in investigations for ischemic colitis?

CT scan, can see complications, free fluid, and see thickening and inflammation

Why are colonoscopies typically avoided in ischemic colitis cases?

Can cause perforation

When should ischemic colitis cases be referred?

Always referred to surgery , watch for perforation , bleeding can be significant

What are hemorrhoids?

Venous cushions that function as gaskets in the continence mechanism. Normal function unless inflamed

What are the symptoms of hemorrhoids?

Swelling, bleeding, pruritus, pain and hygiene

What is valsalva?

Maneuver when holding breath and straining that can cause a hemorrhoid to prolapse

What causes hemorrhoids?

Genetics, dietary fiber, toileting habits, pregnancy and anything that increases intraabdominal pressure

What is important to know around that internal hemorrhoids are not palpable?

They aren’t palpable so it’ll be something else, always exclude cancer in investigations

What are treatment options for hemorrhoids?

Dietary fiber, have for 8 weeks for full response

Take laxatives, limit toilet time, use topical or oral therapies

Sometimes surgery , or ring ligation for internal

What are the red flags of hemorrhoids?

Bright red blood lasting more than 3 months, blood mixed in stool, constitutional symptoms and patient concern. Symptomatic external hems

What is a anal fissure?

Tear in anal canal, sharp pain during and after bowel movement, can be acute and chronic, extremely painful or impossible DRE, most resolve with conservative measures

Hypertonic sphincter causes relative ischemia . Treatment uses things to help relax including topicals or Botox injection and sometimes and internal sphincterotomy

What are red flags for anal fissures?

Lasts longer than 6 weeks, does not respond to treatment, associated mass, immunocompromised, constitutional symptoms or is off the midline

What does it mean if a anal fissure is located off the midline?

Most important red flag. Shows that there is another issue involved causing it, they’ll normally only be in the midline due to ischemic factors, if it’s not then it’s not normal causing

What is the treatment for anal incontinence?

Treat diarrhea and bulk stool. Pelvic floor physio. Lifestyle interventions . Important to rule out neurogenic causes . Refer if it does not improve

What are the risk factors for colorectal neoplasia?

age is the biggest risk, parallel with decade of life

Sex , more common in males

Family history

Smoking/alcohol

Physical activity

Diabetes

IBD

Diet and radiation therapy

What is colorectal neoplasia?

Growth of uncontrolled cells in the colon or rectum (cancer)

What gives protective effects towards colorectal neoplasia?

Vitamin D, NSAIDS, physical activity

What has negative effects towards colorectal neoplasia?

Obesity

Who should be screened for colorectal neoplasia?

High incidence of disease, age 50-74, can tolerate treatment, has a 1st degree relative , screening should start at 40, patients with IBD or polyposis syndromes. If there are symptoms there is no screening

How is screening done for colorectal neoplasm?

Occult blood (FIT test) , colonoscopy is golden standard, ct colon graphy, stool DNA

What are the symptoms of colorectal neoplasm?

Obstruction, change in bowel habits (pencil thin stools, blood PR, alternating diarrhea and constipation), anemia, Metastatic symptoms, perforation, right sided leans more towards bleeding and anemia while left sided is obstruction and change in habits

What sex is more affected by rectal cancer?

Male

What is used to stage colon cancer?

CT chest/abdomen/pelvis, complete colonoscopy, CEA levels (tumour antigen)

What is used to stage rectal cancer?

CT, colonoscopy, CEA and pelvic MRI or ERUS

What is the staging system for colorectal neoplasia?

TNM system

Stage 1 and 2 is localized disease

Stage 3 is regional disease (node spread)

And stage 5 is distant disease (meta)

When is chemotherapy usually done in colorectal neoplasia?

Preop (neoadjuvant) is in locally advanced rectal , 25 treatments and 5 treatments rdiation

Post op (adjuvant) stage 3 and sometimes stage 2, eradication of micrometastes. 5-FU, oxaliplatinin (FOLFOX).

Palliative

Ironitecan (FOLFIRI)

Anti EGFR antibodies and immunotherapy check point inhibitors

When is radiotherapy used for colorectal neoplasia?

Usually in rectal at any stage

What is the key treatment in colon cancer?

Surgery first

What is the key point in treatment for rectal cancer?

Early stage is surgery first, more advanced is chemo first

What is the outcome of stage IV colorectal neoplasia?

Usually palliative, curable in rare cases where complete resection possible. Combination of systematic and local therapy, metastastectony , and complete resection is the only cure, chemo is palliative

What is the outcome of stage IV colorectal neoplasia?

Usually palliative, curable in rare cases where complete resection possible. Combination of systematic and local therapy, metastastectony , and complete resection is the only cure, chemo is palliative

What are anticholingerics?

Prototype is hyoscine, mechanism is to block the mucanaric receptors that stimulate peristalsis

Side effects include dry mouth, urinary retention, and constipation

What are calcium antagonists?

Prototype is pinaverium

Blocks entry of the calcium in smooth muscle contraction

Side effects include constipation and abdominal distension

Serious side effects can be esophageal irritation

What is linaclotide?

Medication used in IBS for both pain and constipation. It’s a cyclic guanosine mono phosphate (cGMP)

Increases intensional secretions and reduces transmission of pain signals

What treats IBS?

Laxatives, anti diarrheal, anticholingerics, calcium antagonists, linaclotide, and antidepressants (if anxiety or depression present as well)

What is IBD treated with?

Antiinflammatories and immunosuppressants

Aminosalicylates, TNF inhibitors, Corticosteroids, and immunosuppressants

What are aminosalicylates?

Originally founded in 1930s and used for rheumatoid arthritis. Mechanism is not established but it’s antiinflammatory . Prototype is 5-aminosalicylic acid (5-ASA) known as mesalamine

Inhibits inflammatory mediators like tumour necrosis factors? Inhibits cyclooxygenase (COX) they act locally so in the colon

Side effects include GI symptoms and headache

What are TNFalpha inhibitors?

Inhibits the important tumour necrosis factor of inflammation (particularly important in IBD), protoype is infliximab

Side effects include Opportunistic infections (Immunosuppressive effects) can reactivate tuberculosis, hypersensitivity reactions, malignancies

What are mabs?

Bind to TNF and prevent it from acting with its receptor to active TNF

What are corticosteroids?

Immunosuppressive and anti inflammatory affects, can be oral, rectal or parenteral. Prototypes are prednisone and budesonide

Side effects are involved more with prednisone than budesonide. There are many potential side effects

What are antimetabolites?

Azathioprine is the prototype, they are immunosuppressants, converted to structural analogue of guanine. False nucleotide halts the DNA and RNA synthesis, immune cells rely on nova purine synthesis and are therefore susceptible to actions of antimetabolites

Side effects are infection and cancer, bone marrow suppression and gastrointestinal cells

How is a disorder of gut-brain interaction diagnosed?

Based on Rome five criteria and exclusion of organic causes. Influenced by sensitizing medical events, genetic predisposition, and sensitizing psychosocial factors

What is the approach to pediatric abdominal pain?

Suspected functional abdominal pain disorder (recurrent abdo pain at least 1 times a week for three weeks with no red flags), evaluate history and physician exam, do work up. If tests are normal determine symptom subset using Rome and treat the bio psycho social

What are the antispasmodics used for chronic abdominal pain in peds?

Hyoscine butylbromide (buscopan) and peppermint oil

What is cryptoheptadine used for?

Effective for abdominal pain, abdominal migraines, and cyclic vomiting syndrome . Can stimulate appetite, weight gain or sedation

What are some red flags for pediatric GERD?

Weight loss, fever, bulging fontanel. Persistent forceful vomitting, hemetaemesis, chronic diarrhea

What is GER?

Passage of gastric contents into the esophagus with or without regurg and vomiting. It’s a normal process in healthy infants, children and adults. No troublesome symptoms, infants typically present unbothered

When are common onset times for functional constipation in pediatrics?

Introduction of solids (around 6 months old), time of toilet training (2-3 years) and school attendance

What’s the typical pathway that leads to constipation in peds?

Withholding to increased water absorption by colonic mucosa to drier and harder stools to stool retention to distension of rectum to lord of recital sensation, fecal incontinence, loss of normal urge, decreased motility (anorexia, abdominal pains and abdominal distension)

What is a concerning red flag for constipation patients in peds?

Abnormal position of the anus

What are the red flags around constipation for peds?

Passage of meconium in more than 48 hours after birth. Constipation starting in first month of life. Family history of Hirschsprung’s disease (congenital where nerve cells are missing from part of baby’s large intestine).ribbon stools. Blood in stools with absent of fissures, failure to thrive. Bilious vomitting, severe distension, abnormal thyroid gland. And normal position of anus. Absent anal reflex. Decreased lower extremity. Anal scars

What is the diagnosis criteria for constipation?

Must include 2 or more of the following to occur at least once per week for a minimum of a month

2 or fewer defecation per week of at least four year old patient. 1 episode of fecal incontinence, history of retentive posturing or excessive volitional stool retention , history of painful or hard bowel movements, presence of large rectal mass. History of large diameter stools that can obstruct toilet

Diagnosis is solely clinical

What is maintenance for constipation in pediatrics?

Educate, ensure good toileting habits. If significant constipation a clean out is mandatory (PEG-3350 at high does for 2-3 days with goal of fully liquid stools)

And start maintenance dose and can continue to 4-6 months

What are the red flags for pediatrics diarrhea?

Bloody stools, night time awakening (concerning for colitis), fever, weight loss, rashes and oral ulcers, and joint swelling

What are key differentials for chronic diarrhea without red flags or failure to thrive?

Toddlers diarrhea (excessive juice), carb intolerance, giardia, irritable bowel syndrome, post infectious diarrhea

What are the key differentials in chronic diarrhea with failure to thrive or red flags?

Celiac, IBD,

What are the most common symptoms for celiac disease in children?

Asymptomatic, abdominal pain, diarrhea, failure to thrive

What is different from celiac diagnosis in children compared to adults?

Children don’t go in for endoscopy