Constipation for undergraduate medical students.pptx

Educational Lecture about constipation for undergraduate medical students

1. Constipation By Dr Monkez M Yousif MD AGAF

2. The Colon’s Role Most literatures state that the colon is 3-5 feet long. Layers of muscles line its wall. The muscle contractions produce movements (motility), helping stool to move through and out of the body.

3. Four main functions of the colon Absorbing water and salt from waste Moving (propelling) waste Storing waste until it is expelled Evacuating waste

4. Definition Constipation is used to describe symptoms that relate to difficulties in defecation including: Infrequent bowel movements, Hard or lumpy stools, Excessive straining, Sensation of incomplete evacuation or blockage, Use of manual maneuvers to facilitate evacuation .

5. Bristol stool chart The Bristol Stool Chart or Bristol Stool Scale is a medical aid designed to classify stools into seven groups. Type 1-2 indicate  constipation , Type 3-4 are  ideal stools  as they are easier to pass, and Type 5-7 may indicate  diarrhoea and urgency . 

6. Constipation may be: Acute, where symptoms typically last less than a week and are commonly precipitated by a change in diet and/or lifestyle (e.g. reduced fiber intake, decreased physical activity, stress, toileting in unfamiliar surroundings). Chronic constipation is generally defined by symptoms that typically lasts >4 weeks or, in accordance with consensus criteria, >3 months.

7. Chronic Constipation Etiology Organic (Secondary) Idiopathic (Primary) likely only if there are symptoms other than constipation NTC STC DD

8. Normal transit time Slow-transit constipation (colonic inertia) Rectal evacuation disorders (Dyssynergic defecation) Primary constipation

9. Bowel transit time The bowel transit time varies, even in the same person. The average transit time through the colon in someone who is not constipated is 30 to 40 hours . Up to a maximum of 72 hours is still considered normal, although transit time in women may reach up to around 100 hours.

10. Secondary constipation Medications: opioids, Ca2+ blockers, α2‑ adrenergic agonists, tricyclic antidepressants, 5‑hydroxytryptamine receptor 3 antagonists, dopaminergic drugs, anticholinergic drugs, neuroleptics and chemotherapeutic agents Disorders of electrolyte balance: hypercalcemia and hypokalaemia Hormonal changes: hypothyroidism and pregnancy Psychiatric disorders: depression and eating disorders Neurological disorders: Parkinson disease, multiple sclerosis and spinal cord injury Ageing: immobility and comorbid conditions Generalized muscle disease: progressive systemic sclerosis and amyloidosis Organic disease of the gastrointestinal tract : colorectal cancer or polyps

11. Rome IV diagnostic criteria for normal-transit constipation Diagnosis of normal-transit constipation requires the presence of the following criteria for the past 3 months with symptom onset >6 months before diagnosis: • Presence of ≥2 of the following criteria: Straining during >25% of defecations Bristol Stool Form (BSF) types 1 and 2 for >25% of defecations Sensation of incomplete evacuation for >25% of defecations Sensation of anorectal obstruction or blockage for >25% of defecations Manual maneuvers to facilitate >25% of defecations (for example, need for digital manipulation or support of the pelvic floor) Less than three spontaneous bowel movements per week.

12. Rome IV diagnostic criteria for irritable bowel syndrome Recurrent abdominal pain on average at least 1 d/ wk in the last 3 mo , associated with 2 or more of the following criteria Related to defecation Associated with a change in the frequency of stool Associated with a change in the form (appearance) of stool These criteria should be fulfilled for the last 3 months with symptom onset at least 6 months before diagnosis. Gastroenterology 2016;150:1393–407.

13. Subtypes of IBS IBS-D (IBS with diarrhea) : where ≥ 25% of bowel movements include diarrhea IBS-C (IBS with constipation) : presence of hard or lumpy stools with ≥ 25% of bowel movements IBS-M (mixed IBS) : patients with alternating diarrhea (≥ 25% of bowel movements) and constipation (≥ 25% of bowel movements) Unsub-typed IBS : insufficient abnormality of stool consistency to meet the definitions for IBS-C, -D or -M

14. Slow Transit Constipation Slow-transit constipation (STC) refers to a delay in transit of stool through the colon, caused by either myopathy or neuropathy, leading to constipation. STC is a rare that causes ineffective colonic propulsion due to deficit and abnormalities of the enteric nervous system (that controls the motility of the large intestine). The etiology of STC remains unclear, our understanding is evolving, and hormonal and autoimmune mechanisms have been proposed. The microbiome may also play a role.

15. Dyssynergic Defecation Clinical symptoms, rectal examination findings, and anorectal physiologic testing suggestive of a pelvic floor disorder

16. Positive stool test for occult blood Positive family history of colorectal cancer Palpable abdominal mass or lymphadenopathy

17. Constipation APPROACH An extensive workup of the constipated patient is performed on an outpatient basis and usually occurs after approximately 3-6 months of failed medical management. Anorectal tests should be used to evaluate for defecatory disorders if over-the-counter agents do not relieve the constipation Imaging studies are used to rule out acute processes that may be causing colonic ileus or to evaluate causes of chronic constipation.  In patients with acute abdominal pain, fever, leukocytosis, or other symptoms suggesting possible systemic or intra-abdominal processes, imaging studies are used to rule out sources of sepsis or intra-abdominal problems. Lower gastrointestinal (GI) endoscopy, colonic transit study, defecography, anorectal manometry, surface anal electromyography (EMG), and balloon expulsion study may be used in the evaluation of constipation. In the acute situation with a patient at low risk who usually is not constipated, no further evaluation is necessary. Consider sigmoidoscopy,  colonoscopy , or barium enema for colorectal cancer screening in patients older than 50 years.

18. Constipation. Note the large amount of stool throughout the colon on this radiograph. Constipation. A large stool mass is visible in the hepatic flexure of the colon. X ray abdomen erect

19. Constipation. Note the distended transverse colon on the computed tomography scan. Constipation. This computed tomography scan reveals a distended rectum. CT ABDOMEN

20. Ample hydration, exercise, and supplementation of dietary fiber (15-25 g/d). Bowel-training regimen: after breakfast, a distraction-free 15-20 min on the toilet without straining is encouraged. Bulk-forming laxatives: Dietary fiber Wheat bran • Methylcellulose Stimulant laxatives (Stimulate motility and intestinal secretion) Bisacodyl, senna and Docusate sodium Lubiprostone (Cl channel activator) Prucalopride (selective 5-HT4 receptor agonist) Linaclotide (guanylate cyclase –C agonist) Treatment Constipation Osmotic laxatives • Magnesium sulphate • Lactulose Suppositories • Bisacodyl • Glycerol Enemas Docusate sodium