أسئلة السادسة GIT الدلتا

Irritable Bowel Syndrome (IBS)

• Chronic illness characterized by abdominal discomfort and disturbed bowel habits.
• Approximately 10% of the global population is affected.

Clinical Features and Rome IV Criteria

• Features include recurrent abdominal pain for at least 1 day per week in the last 3 months.
• Pain is associated with two or more of the following: relation to defecation, change in stool frequency, change in stool form.
• Symptoms must have started at least 6 months prior to diagnosis.

Symptoms Supporting IBS Diagnosis

• Symptoms include abnormal stool frequency and form, difficulties in defecation, passage of mucus.
• Also include bloating or feelings of distension, a long history with relapsing and remitting course, exacerbations triggered by stressful life events.
• Coexistence of anxiety and depression, association with symptoms in other organ systems.
• Symptoms that are aggravated by eating are common.

Pathophysiology

• Intestinal contractile and electrical activity are increased due to increased sensitivity to visceral stimulation.
• Food and stress may trigger symptoms.

Subtypes of IBS

• IBS-C is constipation predominant, with constipation occurring more than 25% of the time.
• IBS-D is diarrhea predominant, with diarrhea occurring more than 25% of the time.
• IBS-M is mixed, with alternating constipation and diarrhea.
• IBS-U is unclassified, applying to patients who meet IBS criteria but cannot be categorized into the above three groups.

Diagnosis

• IBS is not a diagnosis of exclusion; it is based on Rome IV criteria.
• Investigate based on patient age, family history, and presence of 'alarm' symptoms.
• 'Alarm' symptoms include onset after age 50, progressive deterioration, fever, weight loss, and rectal bleeding not caused by fissures or piles.
• Other alarm symptoms are unexplained iron deficiency anemia, nocturnal diarrhea, steatorrhea, and dehydration.

Investigations

• Initial investigations include routine hematology, biochemistry, and sigmoidoscopy with rectal biopsy (if diarrhea).
• If diarrhea is persistent, serum B12 and folic acid levels should be checked.
• Further, iron studies, thyroid function, coeliac antibodies, liver function tests, CRP, and stool analysis can be checked.
• Fecal calprotectin is evaluated in suspected IBS-D cases.
• Consider colonoscopy in suspected IBS-D if fecal calprotectin is high to exclude ulcerative colitis, Crohn's disease and microscopic colitis.
• Fecal urgency or incontinence suggests need for anorectal manometry.

Treatment - Lifestyle Measures and Diet

• Regular exercise, like 20 minutes of walking daily.
• Maintain regular meals, taking time to eat.
• Drink at least 8 cups of fluids daily, especially water or non-caffeinated beverages.
• Restrict tea and coffee to a maximum of 3 cups per day.
• Limit intake of high-fiber foods.
• Consider exclusion diets by eliminating certain foods that increase symptoms.

Treatment - Biofeedback

• Effective in IBS patients, particularly those with IBS-C, who exhibit dys-synergic defecation.

Treatment - Pharmacological Therapies

• Therapies are prescribed according to symptoms.

Abdominal Pain

• Antispasmodics can be used like mebeverine, hyoscine butylbromide, modified-release peppermint oil capsules, or alverine citrate.

IBS-D

• Antidiarrheal agents like Loperamide or Cholestyramine can be administered.

IBS-C

• Treat with laxative agents examples include macrogols.

Pro-secretory Agents

Linaclotide

• Increases intestinal chloride secretion and decreases stimulation of visceral afferent pain fibers.
• Improves constipation, abdominal pain, and bloating without causing diarrhea.
• Dose: 290 micrograms orally daily, 30-60 minutes before breakfast.

Lubiprostone

• Chloride channel activator that stimulates intestinal fluid secretion and improves constipation.
• Dose: 24 micrograms twice daily.

5-HT 4 receptor agonists: Prucalopride

• Improves colonic transit time, constipation, and quality of life.
• Dose: Start at 1mg orally daily, then increase to 2mg orally daily if tolerated.

Antibiotics

• Rifaximin 550mg three times daily improves symptoms.

Antidepressants

• Tricyclics, SSRIs are used.