Constipation (oxford clin cases)

Question 1

What are some pathophysiological reasons someone might be constipated?

Answer 1

Lack of peristalsis
Hard stools
Patient unable to push stool
Bowel obstruction

Question 2

What are some differentials that you may have in mind when a patient presents with constipation?

Answer 2

IBS
Carcinoma 
Low fibre diet 
Dehydration
Secondary to drugs

Question 3

What types of drugs are commonly known to cause constipation?

Answer 3

CCBs
Opiates
Iron supplements
Trycyclic antidepressants 
Anticholinergics

Question 4

What is the most common cause of constipation in a hospital setting?

Answer 4

Patients being embarrassed to defecate eg because they are in earshot of others

Question 5

What is the most common cause of constipation in a GP setting?

Answer 5

Lack of dietary fibre or dehydration

Question 6

What are some red flags when someone has constipation?

Answer 6

Blood in the stool
Intermittent mucoid diarrhoea
Persistent constipation
Absolute constipation
Previous hx of colonic polyps or colon cancer
Family hx of colonic polyps or colon cancer (especially if they were under 60)
Significant weight loss, anaemia (fatigue) or night sweats

Question 7

What is absolute constipation?

Answer 7

When the patient is not passing any faeces or flatus

Question 8

What does absolute constipation suggest is the diagnosis?

Answer 8

Small bowel obstruction

Question 9

What does hard/lumpy stool suggest is the cause of constipation?

Answer 9

Lack of dietary fibre or dehydration

Question 10

What does chronic constipation suggest?

Answer 10

A benign cause

Question 11

What does diarrhoea alongside constipation suggest is the diagnosis?

Answer 11

IBS- especially if the patient is young
Diverticular disease- especially if the patient is old and has left iliac fossa pain
Colorectal cancer- especially if the diarrhoea is mucoid

Question 12

What diagnosis does mucoid diarrhoea alert you to?

Answer 12

Possible colorectal cancer

Question 13

What does tenesmus alongside constipation suggest?

Answer 13

Mass in the rectum

Question 14

What diagnoses does blood in the faeces or on wiping suggest?

Answer 14

Anal fissure
Haemorrhoids
Diverticular disease
Colorectal cancer

Question 15

What diagnosis does feeling cold, tired and weight gain alongside constipation suggest?

Answer 15

Hypothyroidism

Question 16

What does polyuria and thirst alongside constipation suggest is the diagnosis?

Answer 16

Hypercalcaemia

Question 17

What are some signs of hypothyroidism you should look for when examining someone with constipation?

Answer 17

Loss of hair- especially outer 1/3rd of eyebrows 
Brittle hair
Dry skin
Puffy eyes
Malar flush

Question 18

What might you look for on examination if someone has constipation and why?

Answer 18

Abdominal masses- could be carcinoma or impacted faeces
Virchows node- suggest GI malignancy
Anal tone- if lax could be neurological pathology
Abdominal distention- bloating due to IBS
Anal fissure or haemorrhoids
Mass on DRE- colon/rectal cancer

Question 19

What electrolyte imbalances will cause constipation?

Answer 19

Hypercalcaemia

Hypokalemia

Question 20

What investigations might you do if someone presents with constipation?

Answer 20

FBC- masses may bleed and cause anaemia
U+Es- look for hypercalcaemia or hypokalemia
Thyroid function tests- to rule out hypothyroidism
Colon cancer markers
Faecal occult blood test

Question 21

What imaging should always be done if someone has iron deficiency anaemia and why?

Answer 21

OGD- to rule out an upper GI bleed as the cause

Question 22

Up to where is visualised via OGD?

Answer 22

The duodenum

Question 23

What imagine is done for someone after they have been diagnosed with colorectal cancer and why?

Answer 23

PET-CT to see how far it has spread

Also could do an chest, abdomen and pelvis CT

Question 24

What lifestyle changes would you suggest to a patient with constipation caused by low fibre, dehydration and an immobile lifestyle?

Answer 24

Increase dietary fibre by eating more fruits and veg, high fibre cereal, wholemeal bread etc

Try to exercise more eg a brisk 30 min walk everyday

Increase fluid intake

Question 25

What medications can be given for constipation and how do they work?

Answer 25

Osmotic laxatives Stool softners Peristalsis stimulants

Question 26

What is the mechanism of action of osmotic laxatives?

Answer 26

They help retain water in the gut

Question 27

What are some commonly used osmotic laxatives?

Answer 27

Macrogol Lactulose Magnesium salts

Question 28

What is the most common cause of hypothyroidism in young women?

Answer 28

Hashimoto's thyroiditis

Question 29

What are some features of hypothyroidism?

Answer 29

``` Tiredness Carpal tunnel syndrome Constipation Cold intolerance Weight gain Heavy periods ```

Question 30

What are the symptoms of hypercalcaemia and how do you remember them?

Answer 30

Stones, moans, bones and abdominal groans= kidney stones, depression/low mood, aches and pains abdominal pain

Question 31

What are some causes of hypercalcaemia?

Answer 31

Vitamin D overdose Bone metastases Hyperparathyroidism

Question 32

What might you advise a patient if they tell you they have a family hx of colorectal cancer and want to know how they can reduce their risk of developing it?

Answer 32

Have a good diet- high in fibre Stop smoking if they do Exercise adequately and maintain a healthy weight High dose aspirin has also been found to reduce the risk of colorectal cancer however moderate dose will not make a difference

Question 33

What scoring system can be used to stage colorectal cancer?

Answer 33

Duke's criteria