L61, 62 Constipation and diarrhoea

Question 1

61

How is constipation defined?

Answer 1

A symptom-based disorder describing unsatisfactory defecation due to infrequent stools, difficulty passing stools, or a sensation of incomplete emptying. Stools may be hard, dry, and abnormally large or small.

Question 2

61

What is functional constipation?

Answer 2

A functional gastrointestinal disorder where symptoms persist without structural or biochemical abnormalities, classified under the Rome IV criteria.

Question 3

61

What is the prevalence of constipation in the UK and globally?

Answer 3

UK: 1.2–1.3% (GP diagnosis); Global: ~16%; more common in women, elderly, and during pregnancy (affects 40%).

Question 4

61

How much does constipation cost the NHS annually?

Answer 4

£71 million on admissions, £162 million treating the condition, and £91 million on prescription laxatives (2017/18 data).

Question 5

61

Name the types of primary constipation.

Answer 5

Normal transit (functional), slow transit, outlet constipation/anorectal dysfunction.

Question 6

61

What are potential causes/risk factors for constipation?

Answer 6

Lifestyle changes, lack of privacy, anxiety, eating disorders, age, female sex, dehydration, diseases (e.g., MS, hypothyroidism), pregnancy, medication, haemorrhoids, etc.

Question 7

61

Which medications can cause constipation?

Answer 7

Aluminium antacids, anticholinergics, opioids, iron, L-dopa, TCA, phenothiazines, verapamil, 5HT3 antagonists (e.g., ondansetron), among others.

Question 8

61

What are the Rome IV criteria for functional constipation?

Answer 8

At least 2 of the following for >25% of defecations, over 3 months, with onset ≥6 months ago:

• Straining
• Hard/lumpy stools (type 1–2, Bristol chart)
• Incomplete evacuation
• Anorectal blockage
• Manual evacuation
• <3 spontaneous BMs/week

Question 9

61

How do IBS-C and functional constipation overlap?

Answer 9

They share pathophysiological profiles; many patients meet criteria for both. About one-third of cases are reclassified between FC and IBS-C within 12 months.

Question 10

61

When should a patient with constipation be referred to a GP?

Answer 10

• Long-term laxative use
• Blood in stool
• Weight loss, pain
• No flatus
• Alternating diarrhoea and constipation
• Elderly: confusion, retention
• Young: possible IBS
• Suspected obstruction

Question 11

61

How might constipation present in elderly patients?

Answer 11

Confusion, overflow diarrhoea, abdominal pain, urinary retention, nausea, and appetite loss.

Question 12

61

What questions should be asked in a constipation history?

Answer 12

Bowel habits, stool description, symptoms, medication use, diet/lifestyle changes, fluid intake, sensation of incomplete emptying.

Question 13

61

What is the first step in managing constipation according to NICE?

Answer 13

Rule out secondary causes (e.g., medication or illness) and address lifestyle factors.

Question 14

61

What is the general treatment approach for short-term constipation?

Answer 14

1. Bulk laxative + fluids
2. Add/switch to osmotic if needed
3. Add stimulant if stools are hard to pass
4. Reduce laxatives gradually when resolved

Question 15

61

Name types of laxatives with examples.

Answer 15

Stimulants: Senna, bisacodyl

Osmotic: Lactulose, macrogol

Softeners: Docusate, poloxamer

Bulk-forming: Methylcellulose, isphagula

Other: Prucalopride, linaclotide, methylnaltrexone

Question 16

61

How is opioid-induced constipation managed?

Answer 16

Avoid bulk laxatives. Use osmotic + stimulant. Docusate may help. Consider naloxegol or methylnaltrexone if resistant.

Question 17

61

What is naloxegol and how does it work?

Answer 17

Oral peripheral opioid receptor antagonist used for OIC after failed laxative trials. Side effects: abdominal pain, flatulence.

Question 18

61

What is methylnaltrexone and how is it administered?

Answer 18

A subcutaneously administered opioid receptor antagonist with rapid onset (30–60 mins), used when others fail.

Question 19

61

Describe Prucalopride.

Answer 19

A selective 5-HT4 agonist, prokinetic. Used in women with chronic constipation after failing at least two laxative types. Reassess if ineffective after 4 weeks.

Question 20

61

Describe Linaclotide’s mechanism.

Answer 20

Binds to GC-C receptors → ↑cGMP → activates CFTR → ↑Cl⁻/HCO₃⁻ secretion → ↑fluid, ↓pain. Used in moderate-severe IBS-C.

Question 21

61

What bowel habit changes should prompt cancer investigation?

Answer 21

Persistent change, blood in stool, unexplained weight loss, abdominal pain. Early diagnosis increases survival >90%.

Question 22

61

Why should bulk-forming laxatives be avoided in opioid-induced constipation?

Answer 22

They can worsen symptoms due to reduced bowel motility and risk of impaction.

Question 23

61

What are the key counselling points for taking senna and lactulose?

Answer 23

Senna: take at night, effect in 8–12 hours.
Lactulose: may cause flatulence, takes 24–48 hours.

Question 24

61

What specific pelvic issue can cause outlet constipation?

Answer 24

Dysfunction or damage to pelvic floor muscles, e.g., after childbirth or surgery.

Question 25

# 61 What is the significance of methylnaltrexone being a quaternary amine?

Answer 25

It doesn't cross the blood-brain barrier, so it relieves constipation without affecting central opioid analgesia.

Question 26

# 61 A 34-year-old woman presents with infrequent bowel movements and straining during defecation. Her stools are hard (Bristol Stool Chart Type 1), and she reports a sensation of incomplete evacuation. These symptoms have been ongoing for 4 months. What is the most appropriate diagnosis based on the Rome IV criteria? A. Irritable bowel syndrome with constipation (IBS-C) B. Functional constipation C. Secondary constipation D. Normal transit constipation E. Anorectal cancer

Answer 26

✅ Correct answer: B. Functional constipation 📝 Explanation: Rome IV requires ≥2 symptoms present in ≥25% of defecations for ≥3 months, with onset ≥6 months prior. This fits functional constipation.

Question 27

# 61 What percentage of patients initially diagnosed with functional constipation are reclassified as IBS-C or IBS-M within 12 months? A. 10% B. 20% C. 33% D. 50% E. 66%

Answer 27

✅ Correct answer: C. 33% 📝 Explanation: One-third (33%) of patients switch diagnosis within a year (Wong et al., 2010).

Question 28

# 61 Which of the following symptoms in a 60-year-old man with constipation would most urgently require GP referral? A. Uses over-the-counter laxatives B. Haemorrhoids with intermittent bleeding C. Reports alternating constipation and diarrhoea D. Sensation of incomplete emptying E. No bowel movement for 2 days

Answer 28

✅ Correct answer: C. Reports alternating constipation and diarrhoea 📝 Explanation: Especially in the elderly, this may represent spurious diarrhoea from faecal impaction or colorectal malignancy.

Question 29

# 61 Which of the following drugs is least likely to cause constipation? A. Codeine B. Verapamil C. Metformin D. Iron sulphate E. Tricyclic antidepressants

Answer 29

✅ Correct answer: C. Metformin 📝 Explanation: Metformin commonly causes diarrhoea, not constipation.

Question 30

# 61 A 76-year-old woman on amitriptyline presents with confusion, no bowel movement in 5 days, and abdominal discomfort. On examination, the rectum is found to be impacted. What is the most appropriate initial management? A. Prescribe senna tablets B. Start oral macrogol C. Administer a rectal stimulant D. Administer a rectal softener followed by a stimulant E. Increase dietary fibre and fluids

Answer 30

✅ Correct answer: D. Administer a rectal softener followed by a stimulant 📝 Explanation: Impaction requires rectal management. Oral laxatives are less effective when the rectum is loaded.

Question 31

# 61 Prucalopride is used for chronic constipation resistant to laxatives. What is its mechanism of action? A. Guanylate cyclase-C agonist B. Opioid receptor antagonist C. Bulk-forming laxative D. Selective serotonin 5-HT4 receptor agonist E. Osmotic effect by retaining water

Answer 31

✅ Correct answer: D. Selective serotonin 5-HT4 receptor agonist 📝 Explanation: Prucalopride enhances motility via 5-HT4 receptor agonism.

Question 32

# 61 Which of the following best explains why bulk-forming laxatives are contraindicated in opioid-induced constipation? A. They reduce stool fluid content B. They act too slowly C. They can worsen impaction due to decreased bowel motility D. They increase visceral pain E. They interact with opioid receptors

Answer 32

✅ Correct answer: C. They can worsen impaction due to decreased bowel motility 📝 Explanation: Opioids reduce gut motility, and bulk-formers need active motility to be effective.

Question 33

# 61 Linaclotide is most appropriately prescribed in which of the following cases? A. Post-operative faecal impaction B. Chronic opioid-induced constipation C. Functional constipation in pregnancy D. Moderate to severe IBS with constipation E. Suspected bowel obstruction

Answer 33

✅ Correct answer: D. Moderate to severe IBS with constipation 📝 Explanation: Linaclotide is GC-C receptor agonist used for IBS-C; contraindicated in obstruction.

Question 34

# 61 What is the primary action of guanylate cyclase-C agonists in treating constipation? A. Increase mucosal sensitivity B. Increase peristalsis by enhancing serotonin levels C. Promote stool hydration by increasing intestinal fluid secretion D. Enhance bile acid absorption E. Inhibit central pain pathways

Answer 34

✅ Correct answer: C. Promote stool hydration by increasing intestinal fluid secretion 📝 Explanation: GC-C activation → ↑cGMP → activates CFTR → ↑fluid & Cl⁻ secretion → improved motility.

Question 35

# 61 Which of the following is not a recommended question when taking a constipation history? A. Have you recently changed your fluid intake? B. Do you experience any bloating or abdominal discomfort? C. What colour is your urine? D. How often do you open your bowels? E. Have you made any dietary changes?

Answer 35

✅ Correct answer: C. What colour is your urine? 📝 Explanation: While useful in dehydration context, it is not a core question in constipation-specific history.

Question 36

# 61 A 68-year-old man presents to the pharmacy complaining of increasing constipation over the past month. He has recently lost weight, and states that his stools are thinner than usual. He is otherwise well and denies pain. He is self-medicating with senna. What is the most appropriate course of action? A. Recommend switching to macrogol B. Add an osmotic laxative to current regimen C. Reassure and advise increasing fibre intake D. Refer to GP urgently for further investigation E. Recommend stopping senna and starting docusate

Answer 36

✅ Correct answer: D. Refer to GP urgently for further investigation 📝 Explanation: Weight loss and altered stool calibre are red flags — possible colorectal cancer.

Question 37

# 61 A 47-year-old woman with no significant medical history presents with chronic constipation (symptoms for 4 months). She has already tried increasing dietary fibre and fluid intake, but reports no change. She's not on any constipating medication. Her stools are hard, and she finds them difficult to pass. What is the next best step in line with NICE guidance? A. Start stimulant laxative B. Prescribe macrogol C. Start bulk-forming laxative D. Combine stimulant and osmotic E. Prescribe glycerin suppositories

Answer 37

✅ Correct answer: C. Start bulk-forming laxative 📝 Explanation: Stepwise NICE management starts with bulk-former + fluids → osmotic if ineffective → stimulant if still difficult to pass.

Question 38

# 61 Which of the following drugs is correctly matched to its mechanism of action? A. Docusate — osmotic agent B. Lactulose — stimulant laxative C. Bisacodyl — bulk-forming D. Linaclotide — guanylate cyclase-C agonist E. Prucalopride — mu-opioid antagonist ✅ Correct answer: D. Linaclotide — guanylate cyclase-C agonist

Answer 38

✅ Correct answer: D. Linaclotide — guanylate cyclase-C agonist 📝 Explanation: Docusate: stool softener Lactulose: osmotic Bisacodyl: stimulant Prucalopride: selective 5-HT4 agonist

Question 39

# 61 A patient on morphine for metastatic cancer develops opioid-induced constipation (OIC). He has not responded to macrogol and senna. He is not obstructed, and oral intake is normal. What is the most appropriate next treatment option? A. Stop laxatives and try glycerin suppository B. Increase senna dose C. Prescribe naloxegol D. Add lactulose E. Recommend docusate only

Answer 39

✅ Correct answer: C. Prescribe naloxegol 📝 Explanation: Naloxegol is licensed for OIC after failed response to standard laxatives.

Question 40

# 61 Why does methylnaltrexone not reverse analgesia in patients receiving opioids? A. It binds only to 5HT receptors B. It is administered sublingually C. It is metabolised to inactive form D. It cannot cross the blood-brain barrier E. It is a competitive opioid agonist

Answer 40

✅ Correct answer: D. It cannot cross the blood-brain barrier 📝 Explanation: As a quaternary amine, methylnaltrexone acts peripherally only.

Question 41

# 61 A 28-year-old woman presents with bloating, hard stools, and abdominal pain relieved after defecation. Symptoms have been ongoing for 3 months. Which diagnosis is most likely? A. Functional constipation B. IBS-C C. Opioid-induced constipation D. Pelvic floor dysfunction E. Normal transit constipation

Answer 41

✅ Correct answer: B. IBS-C 📝 Explanation: Pain relieved by defecation = classic IBS sign. Rome IV differentiates FC from IBS-C by presence of abdominal pain.

Question 42

# 61 Which of the following is not required for the diagnosis of functional constipation per Rome IV? A. Straining B. Abdominal pain relieved by defecation C. Manual manoeuvres D. <3 bowel movements/week E. Symptoms present for ≥3 months

Answer 42

✅ Correct answer: B. Abdominal pain relieved by defecation 📝 Explanation: That is IBS-C. Rome IV for FC does not include abdominal pain relief as a criterion.

Question 43

# 61 A 55-year-old woman on verapamil presents with new-onset constipation. She has no red flags. You suspect drug-induced constipation. What is the first step according to NICE? A. Add stimulant laxative immediately B. Start linaclotide C. Discontinue verapamil if clinically appropriate D. Prescribe rectal stimulant E. Recommend increasing bulk-formers

Answer 43

✅ Correct answer: C. Discontinue verapamil if clinically appropriate 📝 Explanation: First step is identifying and managing secondary causes (e.g., drugs).

Question 45

# 61 A patient presents with no bowel movement for 4 days, abdominal pain, and no flatus. Which symptom would most strongly suggest bowel obstruction? A. Nausea B. Weight loss C. Severe, colicky pain D. Straining E. Thin stools

Answer 45

✅ Correct answer: C. Severe, colicky pain 📝 Explanation: Absence of flatus and colicky pain = key features of bowel obstruction.

Question 46

# 61 Which scenario represents an inappropriate use of laxatives? A. Short-term use of macrogol in impaction B. Long-term senna use for opioid-induced constipation C. Osmotic + stimulant in palliative care D. Prucalopride in treatment-resistant chronic constipation in women E. Avoiding bulk-formers in dehydrated elderly patient

Answer 46

✅ Correct answer: B. Long-term senna use for opioid-induced constipation 📝 Explanation: Long-term stimulant use risks dependency and colonic hypomotility unless justified (e.g., palliative care).

Question 47

# 62 How does the WHO define diarrhoea?

Answer 47

The passage of three or more loose or liquid stools per day, or more frequent than normal for the individual.

Question 48

# 61 What Bristol Stool Chart type indicates diarrhoea?

Answer 48

Type 5 and above.

Question 49

# 62 What is the difference between acute, persistent, and chronic diarrhoea?

Answer 49

Acute: <14 days Persistent: >14 days Chronic: >4 weeks

Question 50

# 62 Name two causes of increased osmotic load in the gut.

Answer 50

Osmotic laxatives and magnesium-based antacids.

Question 51

# 62 Which infections can cause inflammation of the intestinal lining?

Answer 51

Salmonella, E. coli, protozoal, and viral infections like norovirus.

Question 52

# 62 Name two conditions associated with chronic diarrhoea.

Answer 52

Coeliac disease and irritable bowel syndrome (IBS).

Question 53

# 62 How long do most bacterial or viral diarrhoeal infections last?

Answer 53

2–3 days.

Question 54

# 62 Name a parasite that can cause diarrhoea.

Answer 54

Giardia.

Question 55

# 62 Which bacterial infection is common after antibiotic use, especially in older adults?

Answer 55

Clostridium difficile.

Question 56

# 62 Name three drugs commonly associated with diarrhoea.

Answer 56

Antibiotics, metformin, SSRIs.

Question 57

# 62 Which antacid component is known to cause diarrhoea?

Answer 57

Magnesium.

Question 58

# 62 Name three red flag symptoms for diarrhoea that warrant referral.

Answer 58

Blood in stool Persistent vomiting Diarrhoea lasting more than 6 weeks

Question 59

# 62 What does diarrhoea within 6 hours of eating suggest?

Answer 59

Possible toxin ingestion.

Question 60

# 62 Which factors should be checked when taking a diarrhoea history?

Answer 60

Onset, duration, travel history, fever, recent drugs, red flags.

Question 61

# 62 What is the first line treatment for gastroenteritis in adults?

Answer 61

Oral rehydration therapy (fluids, fruit juice, soups).

Question 62

# 62 When should loperamide be avoided?

Answer 62

If blood or mucus is present in stools or in high fever.

Question 63

# 62 What is the mechanism of action of loperamide?

Answer 63

It decreases propulsive activity in the gut and increases anal sphincter tone via mu-opioid receptor activity.

Question 64

# 62 What is the onset time of loperamide?

Answer 64

Around 1 hour.

Question 65

# 62 What combination does Co-phenotrope contain?

Answer 65

Diphenoxylate and atropine.

Question 66

# 62 How do opioids affect the gut?

Answer 66

Decrease gastric motility, increase fluid absorption, delay defaecation.

Question 67

# 62 Why is codeine not recommended for acute diarrhoea?

Answer 67

Risk of dependence and side effects.

Question 68

# 62 What NICE guideline covers diarrhoea in children under 5?

Answer 68

NICE CG84.

Question 69

# 62 What does oral rehydration therapy (ORT) contain?

Answer 69

Sodium, potassium, chloride, bicarbonate/citrate, and glucose.

Question 70

# 62 What type of fibre is recommended for IBS?

Answer 70

Soluble fibre (e.g. isphagula, oats), avoid insoluble fibre like bran.

Question 71

# 62 What are the typical symptoms of IBS?

Answer 71

Abdominal pain, altered bowel habits (constipation or diarrhoea), bloating.

Question 72

# 62 How does diarrhoea affect oral contraceptive absorption?

Answer 72

It may reduce effectiveness; extra protection is advised if diarrhoea lasts >24 hours.

Question 73

# 62 What mechanism do enterotoxins like those from Vibrio cholerae use to cause diarrhoea?

Answer 73

Activate adenyl cyclase → ↑ cAMP → ↑ chloride secretion into the lumen → water follows osmotically.

Question 74

# 62 How do prostaglandins and ethanol contribute to diarrhoea?

Answer 74

Increase secretory activity and disrupt mucosal integrity.

Question 75

# 62 What is the main physiological reason diarrhoea causes dehydration?

Answer 75

Excess fluid and electrolyte loss exceeds reabsorption in the intestines.

Question 76

# 62 How does increased intestinal motility contribute to diarrhoea?

Answer 76

Reduces contact time for water absorption in the colon.

Question 77

# 62 Why is loperamide generally safe from central opioid effects?

Answer 77

It is a P-glycoprotein substrate and does not cross the blood-brain barrier significantly.

Question 78

# 62 How does loperamide increase non-propulsive motility?

Answer 78

Acts on the myenteric plexus in longitudinal muscle to slow transit.

Question 79

# 62 Why is atropine combined with diphenoxylate in Co-phenotrope?

Answer 79

To discourage overdose by causing unpleasant anticholinergic side effects.

Question 80

# 62 What is the osmolality of UK ORT formulations and why is it important?

Answer 80

~250 mmol/L to reduce the risk of osmotic diarrhoea.

Question 81

# 62 What makes UK ORT solutions different from WHO ORT?

Answer 81

Lower sodium content (50–60 mmol/L vs. 75 mmol/L) – better suited for milder dehydration in the UK.

Question 82

# 62 What signs in infants would prompt urgent referral for gastroenteritis?

Answer 82

Sunken eyes, reduced urine output, lethargy, delayed capillary refill.

Question 83

# 62 Why is lactulose avoided in IBS?

Answer 83

It may worsen bloating and gas due to fermentation in the colon.

Question 84

# 62 What medications might be used to relieve cramping in IBS?

Answer 84

Antispasmodics such as mebeverine or hyoscine.

Question 85

# 62 Why is it recommended to count each day of diarrhoea as a missed pill day?

Answer 85

Because absorption of the hormone may be compromised, reducing contraceptive efficacy.

Question 86

# 62 What is J. Collis Browne’s Mixture and why is it not recommended? What is the legal status of J. Collis Browne’s?

Answer 86

Contains morphine and peppermint oil – discouraged due to opioid content and risk of dependence. Controlled Drug (Invoice P) – exempt from full CD restrictions but must be recorded and retained for 2 years.

Question 87

# 62 A 72-year-old man presents with profuse watery diarrhoea, abdominal pain, and a recent history of amoxicillin use. What is the most appropriate next step? A) Start loperamide immediately B) Prescribe diphenoxylate with atropine C) Refer for stool testing for Clostridium difficile D) Reassure and advise rest and fluids E) Prescribe codeine phosphate

Answer 87

✅ Answer: C – Refer for stool testing for Clostridium difficile Explanation: Elderly patient + recent antibiotics + high-volume diarrhoea = C. difficile suspicion. Antimotility agents (like loperamide) should be avoided due to risk of toxic megacolon.

Question 88

# 62 A 30-year-old woman presents with abdominal discomfort and alternating diarrhoea and constipation. She has no red flags. Which of the following is the most appropriate initial treatment? A) Bran fibre B) Lactulose C) Loperamide D) Diphenoxylate E) Codeine phosphate

Answer 88

✅ Answer: C – Loperamide Explanation: IBS-D treatment includes symptom-targeted therapy. Loperamide is preferred. Avoid lactulose and insoluble fibre like bran, as they may worsen symptoms.

Question 89

# 62 A 28-year-old man has developed diarrhoea six hours after eating from a food truck. He is afebrile and well hydrated. What is the most likely cause? A) Norovirus B) Salmonella spp. C) Toxin-mediated food poisoning D) Giardia lamblia E) Campylobacter jejuni

Answer 89

✅ Answer: C – Toxin-mediated food poisoning Explanation: Symptoms within 6 hours suggest pre-formed toxins (e.g., Bacillus cereus, Staph aureus). In contrast, bacterial infections like Salmonella take longer to develop.

Question 90

# 62 Which drug should be avoided for diarrhoea in a 40-year-old woman presenting with bloody stools and fever? A) Oral rehydration therapy B) Loperamide C) Stool culture D) Referral for medical assessment E) Discontinue current antibiotics

Answer 90

✅ Answer: B – Loperamide Explanation: Antimotility agents are contraindicated in bloody or febrile diarrhoea due to risk of prolonged infection and complications such as toxic megacolon.

Question 91

# 62 A 52-year-old patient presents with chronic diarrhoea, bloating, and weight loss. Blood tests show iron deficiency anaemia. What is the most likely diagnosis? A) Irritable bowel syndrome B) Coeliac disease C) Microscopic colitis D) Bile acid malabsorption E) Colorectal cancer

Answer 91

✅ Answer: B – Coeliac disease Explanation: Chronic diarrhoea, malabsorption features (bloating, iron deficiency), and weight loss point to coeliac disease. Further investigation with TTG antibodies or biopsy is warranted.

Question 92

# 62 A child presents with diarrhoea, no signs of dehydration, and normal vitals. What is the most appropriate management? A) IV fluids B) Antibiotics C) Diphenoxylate D) Oral rehydration therapy E) Loperamide

Answer 92

✅ Answer: D – Oral rehydration therapy Explanation: NICE CG84 recommends ORT in children unless dehydration is severe. Antidiarrhoeal drugs are not used in children under 12.✅ Answer: D – Oral rehydration therapy

Question 93

# 62 A patient with ileo-anal pouch surgery reports night-time leakage. Which agent may help with continence? A) Codeine B) Bulk-forming laxative C) Metronidazole D) Loperamide E) Ranitidine

Answer 93

✅ Answer: D – Loperamide Explanation: Loperamide increases anal sphincter tone and reduces motility, helping with nocturnal incontinence in pouch patients.

Question 94

# 62 Which of the following drugs does not typically cause diarrhoea as a side effect? A) Metformin B) Colchicine C) SSRIs D) Lactulose E) Atropine

Answer 94

✅ Answer: E – Atropine Explanation: Atropine causes constipation due to anticholinergic effects. The others can cause diarrhoea via osmotic, secretory, or motility effects.

Question 95

# 62 A 65-year-old man presents with diarrhoea and significant weight loss. No infection found. He has a family history of bowel cancer. Next best step? A) Start loperamide B) Prescribe isphagula husk C) Refer for urgent colonoscopy D) Begin high-dose probiotics E) Test for coeliac disease

Answer 95

✅ Answer: C – Refer for urgent colonoscopy Explanation: Weight loss, age >60, and family history are red flags. Suspect malignancy and investigate with colonoscopy.

Question 96

# 62 Which pharmacological mechanism is most associated with opioid-induced constipation (and thus, diarrhoea prevention)? A) Increase in chloride secretion B) Inhibition of serotonin reuptake C) Enhanced propulsive motility D) Decreased cholinergic stimulation E) Increased bicarbonate secretion

Answer 96

✅ Answer: D – Decreased cholinergic stimulation Explanation: Opioids reduce peristalsis by decreasing cholinergic stimulation in the gut. They increase water reabsorption and anal sphincter tone.