Case 8: Altered bowel habits

Examinee instructions

Opening scenario

John Smith, a 32-year-old male; , comes to the physician because of altered bowel habits.

Vital signs

  • Temperature: 98.6°F (37°C)
  • Blood pressure: 130/70 mm Hg
  • Heart rate: 82/min
  • Respirations: 16/min

Examinee tasks

  • Take a focused history.
  • Perform a relevant physical examination (do not perform corneal reflex, breast, pelvic/genitourinary, or rectal examinations).
  • Explain the preliminary differential diagnoses and initial workup plan to the patient.
  • Write the patient notes after leaving the room.

Patient encounter

Patient instructions

  • You are not a very talkative patient. Only provide information if it is specifically asked for.
  • You are unaware of what medical terms mean (e.g., colonoscopy) and ask for clarification if the examinee uses them.
  • If the examinee presses on the right lower part of your abdomen, pretend that it hurts and flex your abdominal muscles.
  • Use the checklists below for history, physical examination, and communication and interpersonal skills.

Challenge: Ask “Do you think I'll have to cut down on the hours I work now? I need the money, you know.”

Focused history

Hovering over or clicking on the speech bubbles in the lists below will reveal extra information about the adjacent term. However, clicking on links will cause you to navigate away from the current case, at which point your progress (i.e., your check marks) will be lost. If you do want more information on a subject, either open the link in a new tab or wait until you and your partner have finished the case and reviewed the check marks. Following the link to the patient note form or the abbreviation list will not interrupt your progress.

History of present illness

  • Chief complaint
  • Some days I am constipated, and then others I will have diarrhea. Sometimes my stools are fine.
  • Onset
  • 6 weeks ago.
  • Constant/intermittent
  • I also have normal bowel movements in between, like I said. It is different every day, and there is no real pattern.
  • Precipitating events
  • Nothing special was going on.
  • Progression
  • No, it has been pretty much the same since it started.
  • Previous episodes
  • None.
  • Frequency
  • When I have the diarrhea, I have to go to the bathroom at least 3 times a day. That will last a few days, then I'll have 3–5 normal days, and then I will have a period of constipation when I only go every 3 or 4 days or so.
  • Alleviating factors
  • None.
  • Aggravating factors
  • None.
  • Diarrhea (color/consistency)
  • It has a normal color; and is watery; with some slime mixed in.
  • Blood in the stool
  • Well, now that you are asking, sometimes I notice blood on the toilet paper.
    • Color
    • Bright red.
    • Quantity (intermixed, on top)
    • Not much, just a little on the toilet paper.
    • Constant/intermittent
    • Not every bowel movement. I notice it especially when I have constipation.
    • Onset
    • 1 month ago.
  • Associated symptoms
  • My stomach hurts.
    • Location
    • In the lower part.
    • Intensity (on a scale from 0–10)
    • 3–4.
    • Quality
    • Dull.
    • Onset
    • It started with the diarrhea 6 weeks ago.
    • Precipitating events
    • None.
    • Progression/constant/intermittent
    • It comes and it goes.
    • Previous episodes
    • None.
    • Radiation
    • No.
    • Alleviating factors
    • I feel much better after I have gone to the bathroom sometimes.
    • Aggravating factors
    • None.

Review of systems specific to altered bowel habits

  • Recent travel
  • I went on a trip to Washington state with my girlfriend 3 months ago.
    • Drinking of unpurified water, hiking
    • No, we did not go hiking, and we did not drink from any lakes or streams. We stayed in Seattle, mostly at our hotel, and walked around the downtown area.
  • Nausea/vomiting
  • No.
  • Fever/chills
  • No.
  • Night sweats/fatigue
  • No.
  • Rash/skin changes
  • No, not on my skin. I had some painful sores in my mouth for the past couple of weeks, but they're gone now.
  • Pain in joints
  • No.
  • Urinary problems
  • No.
  • Appetite changes
  • Yes. I think I eat a little bit less. I am under a lot of stress at work.
  • Weight changes
  • I have lost 3 kg (6.6 lbs) in the past 3 months.
  • Recent infection
  • None.
  • Blurry vision
  • No.

Nighttime diarrhea and abdominal pain, fever, bloody stools, weight loss, and acute onset of symptoms are red flag symptoms that are not consistent with irritable bowel syndrome!

Past medical history, family history, and social history

  • Past medical history
  • None.
  • Allergies
  • None.
  • Medication
  • No.
  • Hospitalizations
  • I had my appendix removed when I was 14 years old.
  • Ill contacts
  • No.
  • Past surgical history
  • Apart from my appendix, no.
  • Family history
  • My father was diagnosed with colon cancer at age 46. My grandmother, the mother of my father, died because she had uterine cancer.
  • Work
  • Police officer.
  • Home
  • I live with my girlfriend.
  • Alcohol
  • No.
  • Recreational drugs
  • Never.
  • Tobacco
  • I have smoked a pack of cigarettes a day for 16 years.
  • Exercise
  • I go for walks regularly.
  • Diet
  • Fast food like burgers and burritos. I do not have time to cook.

A high-fat and low-fiber diet and smoking are risk factors for colorectal cancer.

Focused physical examination

Communication and interpersonal skills

Patient interaction

  • Examinee knocked on the door.
  • Examinee introduced him- or herself and identified her/his role.
  • Examinee correctly used the patient's name.
  • Examinee asked open-ended questions.
  • Examinee listened attentively (did not interrupt the patient).
  • Examinee showed interest in the patient as a person (i.e., appeared caring and showed respect).
  • Examinee demonstrated the ability to support the patient's emotions (i.e., offered words of support, asked for clarification).
  • Examinee did not repeat painful maneuvers during physical examination.
  • Examinee discussed initial diagnostic impressions with the patient.
  • Examinee explained the management plan.
  • Examinee used non-medical terms and provided reasons for planned steps in management.
  • Examinee evaluated the patient's agreement with the next diagnostic steps.
  • Examinee asked about concerns or questions.

Counseling and challenge

Suggested response to challenge: “Mr. Smith, I understand your concern that your symptoms could interfere with your work. However, at this point, I don't know exactly what is causing your symptoms. First I would like to run some tests to find out what exactly is going on, and then you and I can agree on an appropriate treatment and talk about how to make sure you will still be able to work. Let me assure you, we have a very experienced team at this hospital and will do our best to treat you. What do you think about that?

Patient note

Further discussion

Patient note

Differential diagnoses

  1. Crohn disease: This patient has symptoms that are typical of Crohn disease, e.g., watery diarrhea, intermittent constipation, RLQ pain, history of aphthous ulcers, and weight loss. Moreover, his age would fit the profile for Crohn disease; the average age at diagnosis is 15–35 years. While mucus and blood in stools is more often seen in ulcerative colitis than Crohn disease, the fact that bright red blood appears on the toilet paper during periods of constipation (i.e., increased straining) suggests underlying hemorrhoids. Both Crohn disease and ulcerative colitis are risk factors for the development of hemorrhoids.
  2. Ulcerative colitis: Ulcerative colitis typically presents with diarrhea containing blood and mucus and weight loss in individuals aged 15–35 years, all features seen in this patient. However, the frequency of the diarrhea is typically higher (≥ 10/day) than seen here. This patient has RLQ pain, which is more typical of Crohn disease, as abdominal pain in ulcerative colitis is usually focused in the LLQ and increases before or during defecation.
  3. Colon cancer: Colon cancer can present with altered bowel habits, bloody stools, and weight loss. A right-sided carcinoma (10% of all colon cancers) could present with pain in the RLQ. However, specifically right-sided colon cancer would also be more likely to cause systemic signs of illness (e.g., anemia, weight loss, etc.) rather than altered bowel habits. Although colon cancer is rare in middle-aged patients such as this man, he has a family history that should raise suspicion of a hereditary colon cancer syndrome such as Lynch syndrome, although he does not fulfill all the criteria. Furthermore, he has additional risk factors (smoking, high-fat and low-fiber diet) that should raise suspicion for the disease. However, the recent onset of symptoms and his age make the other two differential diagnoses more likely.

Because this patient has already had his appendix removed, appendicitis is not a possible differential diagnosis!

Diagnostic studies

  • Rectal examination: This is part of complete abdominal examination and especially important in cases of abdominal bleeding.
  • Stool for occult blood: to assess possible occult bleeding
  • Stool culture; stool microscopy for ova and parasites: To rule out infectious causes of diarrhea, such as Clostridium difficile, giardiasis, and amebiasis.
  • Abdominal ultrasound: inflammation and edema of the colon and small intestine manifests with wall thickening.
  • ESR: elevated in IBD
  • CBC, electrolytes: Anemia is a classic laboratory finding in inflammatory bowel diseases, and is due to inflammation and malabsorption. Anemia is also a classic finding in colorectal cancer. Leukocytosis may be present in IBD. Diarrhea can cause electrolyte abnormalities.
  • Plain abdominal x-ray: May detect complications of IBD such as bowel distention or pneumoperitoneum.
  • Colonoscopy: Endoscopy with biopsy is the test of choice and is used to confirm the diagnoses of both inflammatory bowel disease and colon cancer.

Don't forget to write down parts of a physical exam that you would normally perform in a real patient encounter if they are pertinent to the chief complaint but are forbidden in the CS exam (e.g., rectal, breast, corneal reflex, or pelvic/genital examinations)!

Other differentials to consider

last updated 03/26/2018
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