Which malignancy risk is highest in Peutz-Jeghers syndrome?
Lung cancer only
Brain tumors exclusively
Pancreatic cancer
Thyroid cancer
Peutz-Jeghers syndrome significantly increases risk of pancreatic cancer along with
gastrointestinal and gynecologic malignancies.
A 50-year-old post-total colectomy ileorectal anastomosis develops incontinence (Wexner 14). Proctoscopy: active proctitis (ulcers 3-10 cm). What complication?
Strictureplasty failure
Recurrent proctitis
Radiation proctitis
Ileal pouchitis
Explanation: Recurrent Crohn's proctitis occurs 30-50% post-colectomy; active rectal inflammation causes sphincter dysfunction requiring local therapy or completion proctectomy.
A 67-year-old man with a colostomy notices dark discoloration and loss of bleeding on pinprick testing of the stoma. What is the most likely diagnosis?
Stomal ischemia
Parastomal hernia
Stomal prolapse
Mucocutaneous separation without ischemia
Explanation: Ischemia presents with dusky discoloration and lack of capillary bleeding. It may progress to necrosis requiring urgent revision.
A 63‑year‑old man with a history of cirrhosis, ascites, and a platelet count of 60,000/µL presents with grade III hemorrhoids and intermittent rectal bleeding. Colonoscopy 1 year ago was normal. The colorectal surgeon is considering treatment. Which of the following is the most appropriate initial therapeutic approach?
perform elective open hemorrhoidectomy under general anesthesia
refer the patient for liver‑transplant evaluation and defer local treatment
perform injection sclerotherapy with close monitoring
perform rubber band ligation in the outpatient clinic
Explanation: In patients with cirrhosis and thrombocytopenia, the risk of hemorrhage and poor wound healing after rubber band ligation or excisional hemorrhoidectomy
is high. Injection sclerotherapy, which induces fibrosis and fixation of the hemorrhoidal tissue without deep excision, is preferred because it carries a lower risk of severe bleeding and sepsis. While liver‑transplant evaluation is appropriate for decompensated cirrhosis, it does not preclude local management of symptomatic hemorrhoids. Open hemorrhoidectomy or RBL are relatively contraindicated in this population. The safest approach is therefore sclerotherapy, with close monitoring for any bleeding or signs of infection, and deferral of excisional surgery unless
absolutely necessary.
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A 34-year-old man with medically refractory ulcerative colitis is being evaluated for ileal pouch anal anastomosis (IPAA). He has a history of recurrent perianal fistulas, patchy ileal ulceration on capsule endoscopy, and noncaseating granulomas on prior biopsy. Which factor is the strongest contraindication to IPAA?
Crohn’s disease with fistulizing phenotype
Mild chronic corticosteroid dependence
Previous laparoscopic appendectomy
Well-controlled primary sclerosing cholangitis
Explanation: Crohn’s disease, especially with fistulizing or small bowel involvement, is a major contraindication to IPAA because of high rates of pouch failure, pelvic sepsis, fistula formation, and recurrent disease. Patients with features strongly suggestive of Crohn’s disease are poor candidates for restorative pouch surgery.
A 33-year-old woman with severe Crohn’s disease develops recurrent dehydration after extensive ileal resection and end ileostomy. Laboratory studies reveal sodium 128 mEq/L and bicarbonate 18 mEq/L. Which mechanism most likely explains these abnormalities?
Chronic adrenal insufficiency from biologic therapy
Hyperaldosteronism causing renal sodium wasting
Syndrome of inappropriate antidiuretic hormone secretion
Excessive fluid and electrolyte loss from high-output ileostomy
Explanation: High-output ileostomies after extensive ileal resection may cause substantial sodium and bicarbonate losses leading to dehydration and metabolic acidosis.
Epidemiologic data from SEER database 2015-2025 show rectal cancer incidence rising 2.1% annually in ages 20-49, disproportionately MSI-high tumors. A 42-year- old with de novo rectal adenocarcinoma lacks Lynch criteria. What environmental exposure most contributes to this rectal cancer epidemiologic shift?
Chronic NSAID use
Statin therapy
Antibiotic overuse disrupting microbiome
Plant-based diet prevalence
Explanation: Antibiotic overuse disrupting gut microbiome most contributes to rising rectal cancer incidence in young adults, with dose-response meta-analyses linking cumulative courses to OR 1.8 via Fusobacterium nucleatum enrichment promoting MSI-high carcinogenesis through immune evasion and biofilm formation, explaining sessile serrated/interval cancer patterns absent in screened older cohorts.
A 62-year-old patient reports passive fecal leakage after hemorrhoidectomy performed elsewhere. Examination reveals diminished resting tone but preserved squeeze. Which structure was most likely injured?
Pudendal nerve exclusively
Rectovaginal septum support tissue
Internal anal sphincter during excision
Levator ani muscle complex only
Explanation: Injury to the internal sphincter during anorectal surgery decreases resting pressure and predisposes to passive fecal leakage despite intact voluntary squeeze function.
A patient with chronic radiation proctitis is undergoing hyperbaric oxygen therapy (HBOT). What is the proposed mechanism of HBOT in this setting?
It stimulates the production of more telangiectasias
It kills anaerobic bacteria in the rectal wall
It promotes collagen synthesis and neovascularization (angiogenesis)
It reduces the systemic absorption of nitrogen
Explanation: Chronic radiation injury is characterized by endarteritis obliterans (vascular damage) and tissue hypoxia. HBOT increases the dissolved oxygen content in the plasma, which stimulates the formation of new capillaries (angiogenesis) and promotes fibroblastic activity and collagen synthesis, improving the health and healing capacity of the irradiated tissue.
A 50-year-old patient undergoes stapled hemorrhoidopexy for circumferential
prolapsing hemorrhoids. Compared with excisional hemorrhoidectomy, which complication is uniquely associated with this technique?
Complete elimination of postoperative bleeding risk
Markedly increased rates of external thrombosis only
Rectovaginal or rectal perforation from deep staple placement
Universal postoperative fecal incontinence
Explanation: Stapled hemorrhoidopexy carries risk of full-thickness rectal injury and pelvic sepsis if the staple line incorporates excessive tissue or extends beyond the rectal wall.
Which factor best predicts local recurrence after rectal cancer surgery?
Circumferential margin involvement
Blood type
Tumor color
Patient BMI
Positive circumferential resection margin is the strongest predictor of local
recurrence in rectal cancer.
A 39-year-old man with Crohn’s ileitis presents with hypoalbuminemia, edema, and chronic diarrhea. Laboratory studies reveal albumin 2.1 g/dL. Which mechanism most likely contributes?
Isolated hepatic synthetic failure without bowel disease
Splenic sequestration from portal hypertension
Renal protein loss from diabetic nephropathy
Protein-losing enteropathy from active mucosal inflammation
Explanation: Severe mucosal inflammation in Crohn’s disease may cause protein- losing enteropathy leading to hypoalbuminemia, edema, and malnutrition.
A pathology report for a T3N0 colon cancer shows "tumor budding" at the invasive front. The report classifies this as "High-grade budding (BD3)." How does this affect the patient's clinical management?
Tumor budding is a favorable prognostic sign indicating a strong immune response
BD3 is a high-risk factor that may lead to the recommendation of adjuvant chemotherapy in Stage II
It suggests the tumor is likely to have a high degree of microsatellite instability
Budding is only relevant for Stage 0 (in situ) disease
Explanation: Tumor budding (defined as single cells or clusters of < 5 cells at the invasive front) is an independent negative prognostic factor in colorectal cancer. High-grade budding (BD3, typically defined as ≥ 10 buds in a field of 0.785 mm2) is associated with an increased risk of lymph node metastasis and recurrence, serving as a high-risk feature in Stage II disease.
A 64-year-old man with fecal incontinence undergoes biofeedback therapy. Which mechanism most directly contributes to symptom improvement?
Permanent augmentation of sphincter muscle bulk
Enhanced coordination of pelvic floor contraction and rectal sensation
Fibrotic strengthening of the internal sphincter complex
Mechanical narrowing of the anal canal diameter
Explanation: Biofeedback improves continence through behavioral retraining, enhanced sensory discrimination, and improved coordination of pelvic floor muscles and sphincter contraction.
A 56-year-old woman with diverticulosis presents with LLQ pain, fever 38.2°C. CT: sigmoid wall thickening 4 mm, fat stranding, no abscess/perforation. WBC 14k. What Hinchey classification?
Hinchey Ia (confined pericolic)
Hinchey Ib (intramesenteric abscess)
Hinchey III (purulent peritonitis)
Hinchey II (pelvic abscess)
Explanation: Uncomplicated diverticulitis (Hinchey 0/Ia) pericolic inflammation without drainable collection managed outpatient antibiotics 7 days; 80% resolve without surgery.
A patient with anal squamous carcinoma is HPV positive. Which HPV subtype is most associated?
HPV 6
HPV 16
HPV 42
HPV 11
HPV 16 is strongly associated with anal squamous cell carcinoma and high-grade
dysplasia.
A 58-year-old man undergoes laparoscopic colectomy. He has chronic kidney disease stage 3. Postoperatively, he requires analgesia. Which analgesic strategy best minimizes ileus risk while maintaining effective pain control?
Scheduled intramuscular morphine injections
Continuous high-dose opioid infusion
NSAIDs as sole analgesic therapy
Epidural analgesia with local anesthetic-based infusion
Explanation: Epidural analgesia using local anesthetics reduces sympathetic tone, improves bowel motility, and decreases opioid requirements, thereby lowering ileus risk. Opioid infusions and repeated morphine injections increase ileus risk significantly. NSAIDs alone are insufficient for postoperative pain control after major abdominal surgery and may worsen renal function in CKD patients.
A patient with desmoid tumor is stable but enlarging slowly. Best management?
Active surveillance or medical therapy
Radiation only
No follow-up required
Immediate surgery
Explanation:
Many desmoids can be observed or treated medically unless symptomatic.
A 42-year-old man with 12-year left-sided UC (Montreal E2) presents with bloody diarrhea 12/day, fever 38.5°C, tachycardia 110 bpm. Labs: albumin 2.4 g/dL, CRP 120 mg/L, WBC 18k. Abdominal exam tender without peritonitis. Stool studies negative. What diagnostic criterion confirms severe disease?
Truelove-Witts severe criteria met
CRP >45 mg/L + heart rate >90
Stool frequency >10/day + fever
Albumin <3.0 g/dL
Explanation: Truelove-Witts criteria define severe UC as >6 bloody BMs/day + ≥1 systemic toxicity (HR>90, temp>37.8, Hgb<10.5, ESR>30); predicts 70% medical failure requiring surgery, guiding urgent cyclosporine/steroid rescue.
A 42-year-old woman with known endometriosis presents with 6 months progressive obstipation, bloating, and crampy lower abdominal pain worse menses. CT enterography shows distal sigmoid stricture 2 cm length with upstream dilation to 6 cm, mucosal tethering to uterus. What is the etiology of obstruction?
Endometriosis deep infiltrating bowel
Malignant transformation
Ischemic stricture
Adhesions from prior surgery
Explanation: Deep infiltrating endometriosis causes fibrotic stricture of rectosigmoid (muscularis propria invasion by endometrial glands/stroma), leading to cyclic obstruction in 80% cases; confirmed by MRI with T2 hypointense radial thickening, distinguishing from adhesions.
A 55-year-old patient develops severe subcutaneous emphysema during prolonged robotic colectomy. End tidal CO₂ rises progressively. Which factor most increases risk of this complication?
Open surgical conversion early in procedure
Reduced carbon dioxide flow rate
Low insufflation pressure
Multiple trocar exchanges and prolonged operative time
Explanation: Subcutaneous emphysema results from gas dissection through fascial planes and is associated with prolonged operative time, high insufflation pressure, and repeated trocar manipulation.
A 39-year-old on vedolizumab for UC develops fulminant CMV colitis (IHC 12 inclusions/HPF). Ganciclovir fails. Foscarnet loading dose?
180 mg/kg induction then 90 mg/kg
60 mg/kg BID x10 days
90 mg/kg q12h x14 days
120 mg/kg daily x21 days
Explanation: Foscarnet induction 180 mg/kg x3 days then 90 mg/kg daily achieves CMV clearance in 85% ganciclovir-resistant disease; nephrotoxicity mandates hydration.
A 50-year-old post-IPAA year 5 presents with pouchitis (urgency, 8 BMs/day). Biopsy: neutrophil infiltrate, cryptitis. Fails cipro/metronidazole. What pathology distinguishes chronic pouchitis from Crohn's recurrence?
Granulomatous inflammation
Transmural eosinophils
Atrophic mucosa with crypt loss
Aphthous ulcers
Explanation: Chronic pouchitis shows villous atrophy and crypt dropout mimicking celiac disease from repeated ischemia/inflammation; Crohn's pouchitis features patchy deep ulcers/granulomas distinguishing from antibiotic-responsive acute neutrophilic pouchitis.