A 23-year-old man presents to his primary care physician for evaluation of diarrhea for the past 6 months. The patient complains of lower abdominal pain which he describes as “crampy.” He has had several episodes of loose, watery stools. He also reports an unintentional weight loss of about 3.5 kg in the last 4 months and a subjective fever on some days over the last month. Family history is not suggestive of a similar history. He does not drink alcohol or use illicit drugs but does smoke 1 pack of cigarettes daily. He has not traveled outside of the country and is not on any medications currently. Vital signs are temperature 37.1°C (98.6°F), blood pressure 118/72 mmHg, pulse 112 beats/min, and respirations 18/min. On physical examination, the patient appears calm and malnourished. Abdominal examination reveals mild diffuse tenderness over the abdomen with no guarding or rigidity. Bowel sounds are normal. The remainder of the examination is within normal limits. Lab investigations are ordered, and the patient is referred for colonoscopy.
Which of the following is most likely to be found on the patient’s colonoscopy?
The correct answer is:
E) Segmental pattern of involvement with aphthous and serpiginous ulcers
This patient’s presentation is concerning for Crohn disease, a type of inflammatory bowel disease. It is characterized by watery diarrhea, low grade fever, weight loss and abdominal pain. Examination may reveal diffuse abdominal tenderness, fistulas, fever, and extra-intestinal manifestations. Colonoscopy can show aphthous ulcers, creeping fat, strictures, “cobble stoning” and “skip lesions.” It can involve any part of the gastrointestinal tract and is a transmural inflammation. Definitive diagnosis requires a biopsy.
Answer choice A: Continuous involvement of the mucosa showing friability and crypt abscesses, is incorrect. Ulcerative colitis, also a type of inflammatory bowel disease, presents with a diffuse, superficial involvement of the rectum with friability, edema, and pseudopolyps on colonoscopy. Clinical features usually include bloody diarrhea and tenesmus and there may be frank blood on rectal examination.
Answer choice B: Elevated yellow-white plaques over the colonic mucosa, is incorrect. Pseudomembranous colitis presents with yellow-white plaques over the mucosa on colonoscopy. An important risk factor includes recent treatment with antibiotics such as clindamycin.
Answer choice C: Hundreds of polyps distributed throughout the tract, is incorrect. Hundreds of polyps distributed throughout the GI tract are seen in polyposis syndromes.
Answer choice D: No obvious pathology, is incorrect. This patient has signs and symptoms of Crohn disease which would have the colonoscopy findings mentioned above.
Key Learning Point
Features of Crohn disease on colonoscopy include aphthous ulcers, creeping fat, strictures, “cobblestoning” and “skip lesions” with a transmural involvement of any part of the gastrointestinal tract.
