disorders of the intetines

Difficult, incomplete, or infrequent evacuation of dry and hardened feces from the bowels. Determined by altered consistency more than frequency

Constipation is defines as

• aging slowing transit time

• Neurogenic disorders

• Sedentary lifestyle

• Lower volume diet

Constipation can be caused by/etiology

excessive volume fluidity and frequency of bowel movements where:

• Acute: less than 2 weeks

• Chronic: more than 4 weeks

Diarrhea is defined as

• osmotic or malabsorption

• Secretory tissues

• Motility disorders

• Inflammatory exudation (fluid that oozes from wounds)

Diarrhea can be caused by/etiology

• delayed transit time

• Decreased vol and number of stools

• Decreased motility causing delayed transit

The pathophysiological causes of constipation

• osmotic/malabsorption diminishes

• Secretory will not

Types of diarrhea that do and do not diminish with reducing oral intake

• excess H2O drawn into intestine

• Increased secretion of mucosal fluids and electrolytes

• Increased motility

Pathological causes of diarrhea

Gastrointestinal disorder not explained by structure or biochemical alterations, will have negative physical and lab tests

IBS is defines as

Related to causing serotonin transmitter polymorphisms (genetic)

Brain-gut interaction (mis-interactions) that cause IBS are linked to

• intestinal inflammation

• Visceral hypersensitivity/hyperalgesia

• Motility and secretion abnormalities

• Intestinal infection

• Overgrowth of flora

• Food allergies/intolerances

• Psychosocial

Pathophysiological mechanisms that can lead to IBS

• abdominal pain

• Diarrhea , constipation, or altering predominant

• Gassy, bloating

• Passage of mucus

• History of lactose intolerance, anemia and occult blood in stool

Signs and symptoms of IBS

Recurrent abdominal pain, on average at least 1 day per week in the last 3 months associated with 2+ of the following:

• related to defecation

• Change in stool frequency

• Change in stool appearance

• Symptoms onset at least 6 months prior to diagnosis

The Rome IV diagnostic criteria for IBS

• ulcerative colitis

• Crohn’s disease

The 2 types of IBD

1. Genetic predisposition or unknown environmental factors

2. Abnormal antibacterial activity of ICE & dendritic cells

3. Long inflammatory response by T-cells

4. Release of cytokines IL-1,6 and TNF

5. Regulation of cytokines is irregular

The inflammatory pathogenesis of both IBD types

• TH1

• TH2

• TH17

3 major types of CD4 helper cells for inflammatory pathways in IBD

IL-12

What stimulates TH1

M killer function

Function of TH1

• IL-4, 6, 23

• TGF-beta

What stimulates TH2

B cell activation and generation of antibodies

Function of TH2

• IL-4, 6, 23

• TGF beta

What stimulates TH17

Attracts granulocytes causing chronic inflammation and autoimmunity

Function of TH17

Inhibited my macrophages that release IL-23

Enhanced by IL-10

What inhibits and enhances T regulatory cells

Chronic inflammatory disease that causes superficial ulceration. Limited to the colonic mucosa, usually in the rectum and sigmoid colon

Definition of ulcerative colitis

• genetic

• Altered immune response to normal flora (from TH1 & TH17)

• Smoking

• IL-10 deficiency (immunosuppressant)

• Psychological

Risk factors/ causations of ulcerative colitis & Crohn’s disease

1. Inflammation at base of crypt of lieberkuhn (crypts in intestines)

2. Hyperemic muscosa in area (increased BF & swollen)

3. Edema (swelling), bleeding, cramping, urge to defecate

4. Erosions lead to ulcers, abscess, necrosis of mucosa

Pathogenesis of UC

Mild

Type of UC that involves less mucosa & symptoms are minimal

Severe

Type of UC that may involve the entire colon with many prominent symptoms

TNF alpha

What is released by TH1

• anti-TNF alpha

• Anti-IL-12, 23, 6

• JAK inhibitors (enzymes that regulates immune system)

• Cell trafficking

Managements of UC & CD

Inflammatory disorder than can affect any part of the GI (commonly at the ilium or small intestine), smaller amount of cases so difficult to differentiate from UC.

Definition of Crohn’s disease

• granuloma

• Transmural

• Inflammation spreads to lymphoid tissues forming fistulae & strictures

• Ulcerations form fissures

• Strictures promotes obstruction

Pathogenesis of Crohn’s disease

Segmented inflammation in the colon

Crohn’s colitis Is

Activated neutrophils and macrophages produce inflammation causing tissue injury

What is granuloma in CD

• in UC smoking acts as a protectant, increasing mucus secretion

• In CD it is aggravating

Effects of smoking in UC VS CD

Inflammation begins is sub-mucosa and spreads to mucosa and serosa (all layers of GI is effected)

What is transmural in CD