⭐⭐CONSTIPATION⭐⭐

            ⭐⭐ CONSTIPATION ⭐⭐

1) DEFINITION OF CONSTIPATION :-

    Any 2 of the following criteria should be

    present for >12 weeks :- 

    (a) Less than 3 defecations in a week

    (b) Straining for > 25% defecations

    (c) Hard stools for > 25% defecations

    (d) Sense of incomplete evacuation for

        > 25% defecations

    (e) Sense of anorectal blockade for 

        > 25% defecations

    (f) Digital evacuation of stools (by 

         fingers) for > 25 % defecations.

         

⭐ There are no loose stools in                        constipation⭐

                    

                ⭐⭐⭐⭐⭐⭐⭐

2) CAUSES OF CONSTIPATION :- 

    (a) Acute causes :-                                              (I) Dehydration :- 

           Water in the stool makes it softer

           and helps it to pass more smoothly.

           When there is dehydration, stools 

           become dry and hard . 

           Hence, dehydration is a common

           cause of constipation.

        (II) Acute Intestinal obstruction :- 

           Obstruction in the bowel halts the 

          process of formation and elimination

          of stools.

           Eg - Obstruction due to adhesions,

                  tumors, hernia ,fecal impaction

                  gall stones,etc.

        (III) Acute appendicitis :- 

            Inflammation causes damage to 

            the tissues and affects bowel 

            movements.

    (b) Chronic causes :- 

     ⭐ Functional causes :- (voluntary

           withholding of stools)

        (I) Rectal stasis of stools due to -

             # Faulty habits - not emptying the

                                      bowel regularly

             # Unconsciousness - there is 

                constipation due to obstructed                      defecation, weak abdominal

                muscles, impaired rectal

                sensation and delayed colonic

                transit time.

             # Anal fissure - due to pain &

             spasm of sphincter.

       (II) Colonic stasis - 

            # Inadequate food intake

            # Inadequate fibre intake - Fibre 

            helps to increase the stool weight 

            by causing water retention in the 

            stools & thus decreases colonic

            transit time & easier evacuation of 

            stools.

            # Endocrine disease

            # Irritable bowel syndrome - 

              - Tension, worries & anxiety may 

              precipitate this altered bowel

              movements.

              - In IBS, there may be changes in

              how the intestines move &  

              contract or changes in how the gut

              senses pain. There may be 

              changes in the composition of

              bacteria that are normally found

              in the gut.

              - This may lead to changes in 

              bowel function & constipation.

     ⭐ Organic causes - 

        (I) Endocrine causes - 

            # Diabetes - 

              - Hyperglycemia impairs

               functioning of enteric neuronal

               system and causes autonomic

               neuropathy

              - Loss of functional ICC cells. 

               These are pacemaker cells in git

                which control neuronal input 

               from nerves to smooth muscle

                cells. Thus , they help to control

                intestinal contractions.

              - Diabetes causes smooth muscle

                myopathy.

            # Myxoedema - 

              - In hypothyroidism , intestinal wall

               ( muscle layer) is thickened, 

               thereby increasing the muscle 

               tone and leading to reduced

               intestinal motility

            # Hypercalcaemia - 

              - Calcium deposition in kidney 

                leads to damage to kidney 

                leading to decreased sensitivity

                of kidney towards ADH ( water

                retaining hormone) . This results

                in polyuria and dehydration 

                leading to constipation

              - Calcium ion inhibits sodium 

                reabsorption in PCT and 

                ascending limb of henle loop 

                thus leading to increased sodium

                excretion . Natreuresis causes

                polyuria and thus dehydration.

 

           # Hyperparathyroidism -

             - It results in constipation because 

             of reduction in neuromuscular 

             excitability by high calcium levels.

             High calcium levels can block

             sodium movement through voltage

             gated Sodium channels leading to

             reduced depolarisation & Impaired

             action potential generation.

       (II) Muscular diseases -

           # Amyloidosis -

             - Amyloid deposits in GIT can 

             interfere with function & motility

             of the gut.

             - It can also affect sensory, motor 

             or autonomic nerves leading to 

             their degeneration.

            This all leads to decreased bowel

            movements.

          # Systemic sclerosis -

            - It is an autoimmune disorder 

            leading to neuropathy & myopathy.

            This results in dysmotility of gut &

            constipation.

       (III) Neurological diseases - 

           # Parkinson's disease -

             - Due to changes in dorsal vagal

             nucleus function.

             - Due to loss of dopaminergic 

             neurons. (Dopamine helps in

             controlling muscle movement)

                

           # Hirschsprung disease - 

             - A part of large intestine lacks

             normal nerve cells leading to

             impaired motility of intestine.

      

           # Cerebrovascular disease - 

             - Damaged nerves disrupt the 

             ability of gut to store & get rid of 

             waste.

     

        (IV) Structural disease - 

           # Anal fissure - 

             - Constipation occurs due to pain

             & spasm of spinchter.

 

           # Hemorrhoids (Piles) - 

             - The swollen blood vessels & 

             tissue can bleed & cause bowel

             movements to become painful.

             Thus, leading to constipation.

  

           # Megacolon -

             - There is bowel dysfunction as a 

             result of neurological or muscular

             disorders.

           # Anal stenosis

        (V) Psychological disease - 

            # Depression -

              - Shortage of serotonin in the

              neurons of the gut can lead to

              constipation. (Serotonin is a 

              neurotransmitter)

         (VI) Others - 

              # Tumor pressing on the rectum.

         (VII) Medications - 

              # Anticholinergic drugs - 

                - This medications block the 

                effect of Acetylcholine, a 

               chemical that helps the muscles

               to move. Thus, less movement in 

               the gut leads to constipation.

              # Antihistaminic drugs - 

               - This medications block the

               action of Acetylcholine.

              # Antacids -

                - They can cause disturbances in

                the gut motility leading to

                constipation.

    

             # Calcium Channel Blockers - 

                - These drugs may cause 

                relaxation of the muscles in the

                gut leading to constipation.

 

             # Calcium - 

               - (Refer to hypercalcaemia)

                 ⭐⭐⭐⭐⭐⭐

3) MECHANISMS OF CONSTIPATION :- 

    (a) Primary constipation or functional               constipation - occurs due to

        defect in colonic function or defect in

        anorectal function.

        # Normal transit constipation - stool               moves through colon at regular

           speed.

        # Slow transit constipation - stools

           take longer time to pass through

           the colon . Bowel peristalsis is 

            decreased.

    (b) Secondary constipation - due to

         underlying cause

          # Diabetes

           # Medications

           # fissure, piles

           # neurological causes like                              Parkinson's disease ,etc

     

                 ⭐⭐⭐⭐⭐⭐

4) INVESTIGATIONS OF CONSTIPATION -

    A) History taking - Ask about

       (I) Bowel habits & Fiber intake.

       (II) Water intake. Also examine for 

       signs of dehydration like skin pinch

       test, dryness of tongue.

       (III) Medications.

       (IV) Psychological causes like

       depression. 

       (V) Ask about structural causes

       like piles, fissure, tumor.

       (VI) Ask about history of diabetes or

       thyroid disease.

       (VII) Examine for neurological disease

       like Parkinson's disease - Tremors, 

       Rigidity, Akinesia, Postural Instability.

       (VIII) Ask about symptoms like 

       abdominal pain, bloating, vomiting,

       anorexia, etc.

       (IX) Ask about history of weight gain

       or weight loss, anaemia, blood in stool

       suggestive of carcinoma.

       (X) Ask about any previous surgery.

       (XI) Examine the abdomen by 

       auscultating for bowel sounds & 

       palpating for any swelling, pain

       tenderness or any masses. Rectal

       examination can also be performed.

    B) Colonoscopy, Sigmoidoscopy - 

       To find for 

       (I) Intestinal obstruction.

       (II) Megacolon.

       (III) Tumor pressing on rectum.

       (IV) Stricture.

       (V) Gall stones.

       (VI) Fecal impaction.

       (VII) Colon carcinoma - Rectal 

       bleeding, weight loss, anaemia.

    C) Stool examination - 

       - Dry hard stools.

       - Decreased amount of stool.

       - Tiny rock or pebble like stool.

       - Blood in stool indicates carcinoma.

       

    D) CBC - 

        Inflammatory conditions like

        appendicitis, Inflammatory Bowel 

        diseases.

    E) Other- 

       # Blood glucose - Diabetes.

       # Thyroid hormones - Hypothyroidism.

       # Serum Calcium - Hypercalcaemia,

       Hyperparathyroidism.

       # MRI - Cerebrovascular disease.

       

     F) Colon transit time -

        It measures how long it takes for 

        the food to travel through the colon.

        Special capsules are taken by mouth

        twice a day for 5 days.The capsule

        has X-ray markers. Average transit 

        time is 30 to 40 hrs. Decreased bowel

        movement causes increased colon

        transit time.

 

     G) Anorectal manometry - 

         A catheter with balloon on the end is

         inserted through the anal opening, 

         past the anal sphincter. The balloon 

         is gradually inflated. This causes 

         nerves & muscles in the rectum & 

         anus to begin to squeeze. The end of 

         the tube outside the anus is 

         connected to a machine that records

         the contractions & relaxations of the 

         rectum & anal sphincter. It measures 

         how well the rectum & anal 

         sphincters are working.

       

                   ⭐⭐⭐⭐⭐⭐

5) TREATMENT OF CONSTIPATION -

    A) Treat the underlying cause.

    B) Non pharmacological treatment - 

       (I) Eat fibre rich food - fruits, 

       vegetables.

       (II) Drink plenty of water.

       (III) Train the patient to recognise

       urge to defecate.

       (IV) Advice the patient to defecate in

       the morning when the bowel is active

       & after 30 mins of meals to take

       advantage of gastrocolic reflex.

       (V) Maintain diary of no. of 

       defecations, consistency of stools,

       straining, etc.

       (VI) Patient should be physically 

       active - Exercise is necessary because

       abdominal wall muscles & diaphragm

       play an important role in the process

       of defecation.

    C) Pharmacological treatment -

        (I) Laxatives - 

           # Ispaghula - It makes the stool 

           soft by increasing their water

          content. It also lubricates the

          Intestine which improves the 

          transit of stools.

         

         # Methyl cellulose - It absorbs water 

         in the GIT lumen thereby increasing 

         the bulk of stools.

   

        # Stool softeners (emollient laxative)-

         Docusate.

     (II) Prokinetic agents - 

         Cisapride, Mosapride, Prucalopride.

        They increase the motility of 

        intestine.

    (III) Linaclotide - It is agonist of 

    guanylate cyclase- C receptor on the 

    luminal surface of intestinal 

    enterocytes. It decreases c- GMP levels

    to decrease pain & also accelerates the

    gastrointestinal transit.

   (IV) Lubiprostone - It stimulates type II

    chloride channels in the epithelial cells

    causing an efflux of chloride into the 

    intestinal lumen. The resultant fluid 

    secretion into  the gastrointestinal 

    lumen provides a bolus effect that

    softens the stools & increases the

    intestinal transit.

   

                     ⭐⭐⭐⭐⭐⭐