Understanding Diarrhea: Causes & Effects

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Questions and Answers

What is a key ingredient in oral rehydration solutions that aids active uptake into the intestinal mucosa?

Sodium (correct)

Calcium

Potassium

Magnesium

Which of the following indicates a need for higher level of care evaluation?

Occasional fatigue

Nausea without vomiting

Immunocompromised status (correct)

Recent dietary changes

What does the acronym BRAT stand for in dietary recommendations?

Bananas, Raisins, Almonds, Toast

Bananas, Rice, Applesauce, Toast (correct)

Beans, Rice, Apples, Tea

Bread, Rice, Avocado, Tofu

Which dietary modification is recommended for patients recovering from diarrhea?

Avoid dairy products temporarily Signup and view all the answers

What is a potential indication for performing an abdominal CT scan or endoscopy?

Inflammatory diarrhea Signup and view all the answers

What is the purpose of rehydration in the treatment of diarrhea?

To restore necessary fluids and electrolytes Signup and view all the answers

What should be done with Gatorade in the context of oral rehydration?

Dilute it due to high carbohydrate content Signup and view all the answers

What is a symptom that does NOT necessarily indicate severe cases requiring further evaluation?

Recent antibiotic use Signup and view all the answers

What is the primary concern for the patient described in the case?

Constipation Signup and view all the answers

Which medication is most likely contributing to this patient’s constipation?

Oxycodone Signup and view all the answers

What is considered a common cause of constipation in patients?

Neurogenic causes Signup and view all the answers

Which of the following therapies is indicated to manage this patient’s constipation?

Methylnaltrexone injection Signup and view all the answers

Which symptom is NOT typically associated with constipation?

Frequent bowel movements Signup and view all the answers

What potential metabolic disorder could be a contributing factor to this patient's constipation?

Hypokalemia Signup and view all the answers

What lifestyle factor can contribute to constipation?

Reduced fiber intake Signup and view all the answers

What characterizes diarrhea?

Increased frequency and decreased consistency of faecal discharge Signup and view all the answers

What is the normal presentation of bowel movements for a healthy adult?

Daily or every other day Signup and view all the answers

What is considered acute diarrhea?

Less than 72 hours to 14 days Signup and view all the answers

Which symptom was NOT reported in the clinical case presented?

Blood in stool Signup and view all the answers

How does the pathophysiology of diarrhea primarily occur?

Imbalance in absorption and secretion of water and electrolytes Signup and view all the answers

What pharmacologic agent is appropriate for managing symptoms of diarrhea?

Antibiotics Signup and view all the answers

What is the typical frequency of stool passage associated with diarrhea?

More than three times a day Signup and view all the answers

Which approach is likely NOT part of the treatment goals for diarrhea?

Increasing solid food intake immediately Signup and view all the answers

What was reported as a symptom of the patient in the clinical case?

Weakness and dizziness upon standing Signup and view all the answers

What is the primary dietary recommendation with the BRAT diet?

Avoid fatty and greasy foods Signup and view all the answers

Which drug is indicated for moderate to severe non-invasive diarrhea?

Diphenoxylate + atropine Signup and view all the answers

What mechanism does loperamide utilize to manage diarrhea?

μ-Receptor agonist Signup and view all the answers

What is a significant adverse effect of the drug diphenoxylate + atropine?

Respiratory depression Signup and view all the answers

Which medication is indicated for the prevention of traveler's diarrhea?

Bismuth subsalicylate Signup and view all the answers

What is the primary indication for octreotide?

Tumor-associated diarrhea Signup and view all the answers

What should be avoided when experiencing suspected invasive infection?

Anti-motility agents Signup and view all the answers

Which drug is specifically noted for adverse effects related to stool discoloration?

Bismuth subsalicylate Signup and view all the answers

What is a precaution for the drug Bismuth subsalicylate?

Avoid during lactation Signup and view all the answers

Which medication is used for lactose deficiency or intolerance?

Lactase enzyme Signup and view all the answers

What is a recommended dietary modification for preventing constipation?

Increase fiber intake to at least 20-30 g/day Signup and view all the answers

Which symptom indicates a potential serious underlying issue that should be assessed?

Blood in the stool Signup and view all the answers

What is identified as a non-pharmacological treatment for constipation?

Regular exercise 3–5 days/week Signup and view all the answers

Which statement about dietary modifications is true?

Fiber should be continued for at least 1 month to evaluate effects Signup and view all the answers

What should be assessed if a patient presents with considerable pain or cramping?

Potential gastrointestinal issues or obstruction Signup and view all the answers

What is a key goal of treating acute constipation?

To relieve symptoms and restore normal bowel function Signup and view all the answers

What should be corrected if endocrine and metabolic derangements are present?

Treat the underlying disease Signup and view all the answers

Which factor is important when choosing drug therapy for constipation?

Desired onset of action and patient preference Signup and view all the answers

What is the primary indication for saline osmotic laxatives?

Acute or intermittent constipation Signup and view all the answers

Which osmotic laxative has the fastest onset of action?

Glycerin Signup and view all the answers

What is a common side effect associated with lactulose?

Gas and bloating Signup and view all the answers

What is the typical onset time for bisacodyl when taken orally?

6–12 hours Signup and view all the answers

What condition can be potentially caused by oral sodium phosphate?

Acute phosphate nephropathy Signup and view all the answers

Which bulk-forming laxative requires adequate water intake to be effective?

Calcium polycarbophil Signup and view all the answers

What is the main mechanism of action for lubiprostone?

Activates chloride channels Signup and view all the answers

What is an important consideration before using lubiprostone?

Negative pregnancy test Signup and view all the answers

Which of the following is used for opioid-induced constipation?

Methylnaltrexone Signup and view all the answers

Which agent is commonly used to prevent straining in certain patient populations?

Docusate sodium Signup and view all the answers

Study Notes

Diarrhea

Diarrhea is an increased frequency and decreased consistency of fecal discharge compared to a person's normal bowel pattern.
Frequency and consistency vary between individuals.
Some people have bowel movements up to 3 times a day while others only 2-3 times a week.
Diarrhea involves an alteration in normal bowel movements, characterized by increased water content, volume, or frequency (more than three per day) of stool.
Acute diarrhea lasts less than 72 hours to 14 days.
Chronic diarrhea lasts more than 14 – 30 days.
Pathophysiology involves an imbalance in water and electrolyte absorption and secretion.
Diarrhea can be associated with a specific disease in the gastrointestinal tract or other diseases outside of the gastrointestinal tract.
Mechanisms include changes in active ion transport, intestinal motility, luminal osmolarity, and tissue hydrostatic pressure.
Classification includes secretory, osmotic, exudative/inflammatory, and altered motility/motor categories.

Diarrhea - Classification

Secretory: Secondary to enhanced secretion by intestinal mucosa, often large watery volume with electrolyte loss. Common causes include bacterial/viral/bacterial enteritis, gastric hypersecretion, carcinoid, stimulant laxatives, bile acid malabsorption, celiac disease, IBD (mucosal).
Osmotic: Secondary to hyperosmolar gradient in intestinal lumen; common causes include osmotic laxatives, carbohydrate malabsorption (e.g., lactase deficiency), fat malabsorption (e.g., pancreatic insufficiency), short bowel syndrome.
Exudative/inflammatory: Secondary to intestinal mucosa inflammation or infiltration/invasion. Common causes include IBD, invasive infection (e.g., C. difficile toxin, enterotoxigenic Escherichia coli), cytomegalovirus, Shigella, ischemic colitis, radiation enterocolitis, neoplasm.
Altered motility/motor: Secondary to autonomic nerve dysfunction. Common causes include diabetic neuropathy, post-vagotomy, hyperthyroidism, irritable bowel syndrome (IBS), Addison disease.

Diarrhea - Drug-Induced

Medications that can cause diarrhea include antibiotics, antineoplastics, laxatives, levothyroxine (overreplacement), metoclopramide, acarbose or miglitol, NSAIDs, digoxin, prostaglandins (misoprostol), colchicine, orlistat, sorbitol (sugar-free products).

Diarrhea - Diagnosis

Thorough patient history, including disease and drug-induced causes, recent travel history, and temporal relation to food intake.
Assess fluid and electrolyte status.
Conduct complete blood count, stool culture, and check for ova/parasites if infection is suspected.
If infection is suspected, confirm presence of C. difficile toxin and culture, especially if recent antibiotic use or hospitalization.
Assess stool pH, electrolytes, osmolarity, and fat content if indicated.
Imaging (e.g., abdominal CT scan) or endoscopy with biopsy might be indicated in severe cases, particularly related to inflammatory diarrhea or suspected neoplasm or celiac disease.

Diarrhea - Pharmacist Role

Refer to higher level of care if patient is immunocompromised, paediatric, pregnant, has fever, blood in stool, weight loss >5%, or a suspected invasive infection.

Diarrhea - Treatment (General)

Remove or treat underlying cause.
Rehydrate, using intravenous fluids for hospitalized patients and oral rehydration for others who haven't vomited. Sodium and glucose are key ingredients in oral rehydration solutions.
Dietary modifications: avoid dairy products (may have transient lactase deficiency).
"BRAT" diet for adults (bananas, rice, applesauce, toast).

Diarrhea - Drug Therapy

Loperamide: µ-receptor agonist for mild to moderate non-invasive diarrhea; adjunctive to other non-opioid therapies. Avoid in suspected invasive infection. Pregnancy category B.
Diphenoxylate + atropine: µ-receptor agonist for moderate to severe non-invasive diarrhea; used when loperamide is ineffective. CNS effects, respiratory depression, constipation, and anticholinergic effects with atropine are possible adverse effects.
Bismuth subsalicylate: Anti-secretory, binds toxins; for mild-moderate diarrhea and traveler's diarrhea prevention. Adverse effect: stool discoloration. Avoid in salicylate allergy, pregnancy, or nursing, and in those <12 years old. Use with caution with anticoagulants.
Octreotide: Antisecretory, hormone release suppression; for tumor-associated diarrhea (e.g., VIPoma, carcinoid, HIV-associated diarrhea). Adverse effects: hyperglycemia, gallstone formation.

Diarrhea - Drug Therapy (Additional)

Lactase enzymes: For lactase deficiency or intolerance.
Probiotics (Lactobacilli, Saccharomyces): May help prevent antibiotic-associated diarrhea by competing with pathogens

Constipation

Constipation is a reduction in frequency of bowel movements compared to normal frequency, characterized by difficulty evacuating, straining, hard, dry stools, abdominal pain/distension, low back pain, and anorexia.

Constipation – Pathophysiology

Common causes include altered motility (e.g., ileus), neurogenic causes (autonomic neuropathies, Parkinson's disease), endocrine/metabolic disorders (e.g., hypothyroidism, diabetes, hypokalemia, hypercalcemia, uremia), pregnancy, psychogenic causes, structural abnormalities or obstruction, nutritional factors (reduced fiber/water intake), medications.

Constipation – Diagnosis

Thorough patient history.
Fluid and electrolyte assessment.
Thyroid function assessment.
Imaging (e.g., abdominal CT scan, radiograph) for ileus, obstruction, or dilation.
Refer for further evaluation for those with symptoms lasting more than 1-2 weeks despite treatment, considerable pain/cramping, pregnancy, fever, blood in stool, reduction in stool caliber, weight loss, paraplegia, or quadriplegia.

Constipation – Treatment (General)

Treat underlying disease.
Alter lifestyle factors (particularly diet).
Prevent further constipations.
Acute constipation relief with tap-water enema or glycerin suppository, or use oral sorbitol, low-dose bisacodyl or senna, or saline laxatives (e.g., milk of magnesia).
Address if not due to an underlying disease by treating as an adult, emphasizing high-fiber diet.

Constipation – Treatment – Non-Pharmacological

Dietary modification: increase fiber intake (20-30 g/day).
Adequate and increasing fluid intake (6-8 glasses of water daily).
Exercise (3-5 days/week).
Adjustment of bowel habits.

Constipation – Treatment – Pharmacotherapy

Saline osmotic laxatives: Magnesium citrate, magnesium hydroxide, and sodium phosphate. Use for acute or intermittent constipation, preoperative/pre-procedure bowel preparation (fast onset, 15 minutes to 3 hours). Avoid if renal impairment, heart failure (HF), or cirrhosis.
Other Osmotic Laxatives: Glycerin (management of acute/intermittent constipation; used for pediatric patients as a suppository; fast onset - within 1 hour). Lactulose (management of acute, intermittent, or chronic constipation; preferred in chronic liver disease (onset 1-2 days, multiple doses may be required); associated with gas/bloating; syrup or powder form).
Stimulant laxatives: Bisacodyl (short-term relief of acute/intermittent constipation). Senna (short-term relief of acute/intermittent constipation and long-term prevention of opioid-induced constipation). Possible side effects: abdominal cramping, electrolyte disturbances, and melanosis coli.
Bulk-forming laxatives: Psyllium, inulin, wheat dextrin, calcium poly-carbophil, and methylcellulose; used for intermittent/chronic constipation. Onset 12-72 hours and requires adequate water intake; safe for renal/hepatic disease, pregnancy, and senior citizens; may cause gas/bloating).

Constipation – Miscellaneous Agents

Docusate sodium/potassium: For opioid-induced constipation prevention (combination); used in preventing straining in post-MI, postsurgical, and pregnant patients. Requires adequate water intake for efficacy (onset 1-6 days).
Methylnaltrexone (Relistor): Opioid-induced constipation; Peripheral opiate antagonist; will not reverse central analgesia; given subcutaneously every other day (onset within 4 hours in ~50% of patients).
Lubiprostone (Amitiza): For chronic idiopathic constipation and IBS-C; likely in women over 18; increases intestinal fluid secretion by activating Chloride Channel and may decrease bloating and abdominal pain (adverse effect: nausea). Need a negative pregnancy test (only use with a negative pregnancy test).
Linaclotide (Linzess): For IBS-C and chronic idiopathic constipation. Increases fluid secretion and transit time. Take on an empty stomach 30 minutes prior to meal. Contraindicated in pediatric patients under 6 years old and patients with mechanical obstructions. Do not use in those aged 6-17 years old. Pregnancy category C.

Drug Therapy (General)

Select drugs based on desired action, patient preference and any potential contraindications.
Consider special populations.
Educate patients on alternative forms such as enemas or suppositories.

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Description

This quiz explores the various aspects of diarrhea, including its definitions, classifications, and underlying mechanisms. It differentiates between acute and chronic diarrhea and highlights the physiological changes involved. Test your knowledge on this important gastrointestinal topic.