Q4. Constipation and IBS

Which of the following statements concerning constipation is not true? A patient with new onset of constipation should be suspected as having a structural etiology. Most constipation is due to inadequate intake of fiber, water and food as well as immobility. Ano-rectal motility studies should be performed on patients complaining of constipation. Patients complaining of long standing constipation with significant abdominal pain should be considered to have Irritable Bowel Syndrome. Initial therapy of constipation should include increasing stool bulk (fiber), increased fluid intake and exercise.

C All are true except C. Ano-rectal motility studies are probably best reserved for patients with life long complaints of constipation. This test is necessary to rule out Hirshprung's disease.

Which of the following compounds does not promote(s) constipation? Codeine Antidepressants (e.g., Elavil.) Oral iron sulfate Lactose foods

D A, B and C are correct. Codeine (why heroin addicts are frequently constipated) and anti-depressants slow intestinal transit. Codeine binds GI tract to µ receptors. Many antidepressants have anti-cholinergic effects which also slow intestinal transport.

A 27 year old woman comes the you because of three years of intermittent, mild, diffuse abdominal cramps and bloating. Her symptoms occur after meals and are relieved with bowel movements. She also has constipation 4 - 6 times per month. The constipation resolves spontaneously, but afterwards she has diarrhea for 1-2 days. She has no other symptoms, no history of serious illness and is on no medications. Physical exam is normal. Which of the following is the most likely diagnosis? Colon Cancer Diverticulosis Inflammatory Bowel Disease Inflammatory Bowel Syndrome Lactose deficiency

D The history is classical for IBS. Diarrhea alternating with constipation is common. IBS patients have no evidence of organic disease therefore the physical exam and laboratory studies will be normal. Typical laboratory studies done include complete blood counts, sedimentation rate, stool for occult blood, serum electrolyte and liver tests. These should all be normal in patients with IBS. Advanced imaging tests (CAT, MRI, ultrasound) as well as colonoscopy and upper endoscopy are not indicated. Some physicians may do an office sigmoidoscopy depending on the clinical history. What is the treatment for IBS??

A 30 year old man with a long history of IV heroin use complains of constipation. A flat plat of the abdomen shows stool throughout the colon. Heroin inhibits bowel motility and causes constipation by the following mechanism? inhibition of µ (mu) receptors inhibition of κ (kappa) receptors partial agoinist-antagonist action on µ receptors stimulation of κ receptors stimulation of µ receptors

E Naloxone and naltrexone inhibit µ receptors. Buprenorphine is a partial agonist-antagonist of µ receptors and is used in drug treatment programs to wean heroin addicts. Review of Opioid Analgesics: Opiods act as agonists at opiod receptors (mu=morphine, delta = enkephalin, kappa = dynorphin) to modulate synaptic transmission - open K+ channels, close Ca+2 channels leading to decreased synaptic transmission. This will inhibit release of ACh, NE, 5-HT, glutamate, Substance P. They are used for pain, cough suppression, diarrhea, acute pulmonary edema. Toxicity include addiction, respiratory depression, constipation, CNS depression. Toxicity treatment is with naltrexone or naloxone.

All of the following are true concerning Irritable bowel syndrome EXCEPT: Can be associated with and is a common cause of constipation. Can be associated with rectal bleeding. Can be associated with diarrhea. Occasionally causes mucus per rectum. All are true. A, C, D are true

F Irritable bowel syndrome (IBS) is a functional disorder and the most common reason patients see gastroenterologists. The finding of blood or pus in the stool is not found in IBS and means there is an organic disorder. IBS is defined as recurrent abdominal pain with 2 of the following - pain improves with defecation, change in stool frequency (diarrhea or constipation), change in appearance of the stool. There may be diarrhea, constipation or alternating diarrhea and constipation. This is a chronic disease and no structural abnormalities are found in the GI tract. Treatment is symptomatic.

An intestinal motility study demonstrating an increased prolonged propagated contractions (PPC's) is diagnostic of IBS. True False

False

In the US, IBS is predominantly a syndrome of young men. True False

False

Irritable Bowel Syndrome (IBS) patients experience more discomfort during rectosigmoid balloon distension than people without IBS because they have a generalized intolerance to pain. True False

False

Patients with IBS need to be monitored frequently as they are likely to develop other gastrointestinal diseases. An increase in symptoms should lead to a prompt investigation for another diagnosis. True False

False

People with chronic functional constipation have a three fold increased risk of colon cancer. True False

False

The most important aspect of managing a patient with IBS is initiating a high fiber diet and stressing the importance of compliance with this regimen. True False

False Symptom based therapy and reassurance are key to therapy.

IBS is a common condition accounting for 10-25% of primary care visits and 25-40% of visits for a gastroenterologist in the U.S. True False

True

The underlying pathophysiology of IBS appears to be related to a combination of altered motility in patients with altered visceral perception. The likelihood that one will seek medical care is strongly affected by psychosocial issues. True False

True