# A nurse is assessing a 52-year-old client who has been experiencing changes in bowel habits for the past 3 months. Which assessment finding would be most concerning and require immediate further evaluation for possible colorectal cancer? > source: MyMerci (mymerci.kr) > url: https://mymerci.kr/pages/nclex_q.php?qn_id=540728 > language: ko > subject: Adult Health ## 문제 A nurse is assessing a 52-year-old client who has been experiencing changes in bowel habits for the past 3 months. Which assessment finding would be most concerning and require immediate further evaluation for possible colorectal cancer? ## 보기 1. Occasional constipation alternating with normal bowel movements 2. Dark, tarry stools with a strong odor occurring daily for 2 weeks **✔ 정답** 3. Increased frequency of bowel movements from once daily to twice daily 4. Mild abdominal cramping that occurs after eating spicy foods **정답: 2** ## 해설 Dark, tarry stools (melena) suggest upper GI bleeding requiring immediate evaluation for possible advanced colorectal cancer. Other findings are less specific for urgent cancer assessment. ## 심화 해설 Key Assessment Finding The most concerning finding is dark, tarry stools (melena) occurring daily for 2 weeks. This represents a classic presentation of upper or proximal lower gastrointestinal bleeding, which requires immediate further evaluation for possible colorectal cancer. Why This Finding Is Alarming Dark, tarry stools indicate the presence of digested blood, typically originating from a bleeding source proximal to the ligament of Treitz or from a slow-bleeding lesion in the right colon. In the context of a 52-year-old client with a 3-month history of altered bowel habits, this finding raises strong suspicion for an ulcerated, bleeding colorectal malignancy. The case report by Aso et al. illustrates this exact clinical scenario: a patient presented with melena and was subsequently found to have a sigmoid colon cancer that had invaded the duodenum, forming a malignant fistula [1]. This demonstrates that melena can be the sentinel sign of an advanced colorectal tumor, even when the primary lesion is in the distal colon, due to fistulization or significant intraluminal bleeding that undergoes digestive breakdown during transit. Pathophysiology and Clinical Correlation The mechanism of melena in colorectal cancer involves tumor neovascularization, which creates fragile blood vessels prone to rupture. As the tumor grows, it can ulcerate and bleed slowly into the bowel lumen. The blood is then acted upon by digestive enzymes and colonic bacteria, oxidizing hemoglobin to hematin, which produces the characteristic black, tarry appearance and strong, distinct odor. The daily occurrence over two weeks signifies persistent, clinically significant blood loss, which can lead to iron-deficiency anemia and hemodynamic instability. In the referenced case, the melena was not from a simple mucosal erosion but from a direct tumor invasion into the duodenum, highlighting how a sigmoid colon cancer can produce upper-GI-type bleeding [1]. This underscores the critical need for the nurse to recognize that melena is never a benign finding in an adult with a change in bowel habits; it mandates urgent endoscopic evaluation to rule out malignancy. Differential Analysis of Other Options The other options, while requiring assessment, lack the specificity and urgency of melena for detecting colorectal cancer. - **Option 1: Occasional constipation alternating with normal bowel movements.** This pattern is common in functional gastrointestinal disorders like irritable bowel syndrome (IBS). While a change in bowel habits is a red flag, the intermittent and non-progressive nature, with periods of normalcy, makes it less immediately concerning for a structural lesion like cancer. - **Option 3: Increased frequency from once to twice daily.** A mild increase in stool frequency is a nonspecific change that can be related to dietary modifications, stress, or benign conditions. It does not carry the same weight as evidence of gastrointestinal bleeding. - **Option 4: Mild abdominal cramping after eating spicy foods.** This symptom is highly suggestive of a dietary intolerance or a benign condition like gastritis or IBS. The clear trigger (spicy foods) and the mild, self-limiting nature of the pain point away from an invasive neoplastic process. The nurse must prioritize the finding that indicates active, ongoing blood loss, as this is a cardinal sign of an ulcerated malignancy and a medical emergency requiring prompt intervention. Nursing Implications and Immediate Actions Upon identifying melena, the nurse's priority is to stabilize the client and facilitate rapid diagnosis. This includes assessing vital signs for signs of hypovolemia (tachycardia, hypotension), checking orthostatic vital signs, and monitoring hemoglobin and hematocrit levels. The nurse should verify the stool for occult blood if not grossly apparent and prepare the client for urgent diagnostic procedures. As demonstrated in the case by Aso et al., the diagnostic workup for melena with suspected colorectal cancer involves both upper and lower gastrointestinal endoscopy to locate the bleeding source and obtain tissue for biopsy [1]. The finding of a circumferential tumor on endoscopy, as in the case report, confirms the diagnosis and guides surgical or oncological management. The nurse plays a vital role in client education, explaining the purpose of these procedures, ensuring informed consent, and providing emotional support given the anxiety associated with a potential cancer diagnosis. References (research sources) - [1]Curative Surgery for Malignant Sigmoid-Duodenal Fistula Caused by Colon Cancer: A Case Report.Case reportAso S, Tasaki M, Aso K, Ito Y, Shirakawa S, Kawamitsu K, Noro T, Machida M, Sugo H. (2026) · DOI: 10.70352/scrj.cr.26-0218 ## 임상 시나리오 Melena in Colorectal CancerRecognizing a Critical Alarm Symptom In a client over 50 with a 3-month history of altered bowel habits, the onset of melena is a critical alarm symptom. Dark, tarry stools indicate digested blood from a bleeding source, often proximal to the ligament of Treitz or a slow-bleeding right colon lesion, and require immediate investigation for colorectal cancer. The pathophysiology involves tumor neovascularization creating fragile vessels that ulcerate and bleed. As blood transits the bowel, digestive enzymes and bacteria oxidize hemoglobin, producing the characteristic black, tarry appearance with a distinct foul odor. CautionNever dismiss melena as a minor issue. Even with a distal colon tumor, a malignant fistula or significant intraluminal bleeding can present as melena. Immediate diagnostic colonoscopy is indicated, not a trial of dietary modification or antacids. ## 핵심 개념 - **Melena** — The passage of black, tarry, foul-smelling stools containing digested blood, indicating upper or mid-lower gastrointestinal bleeding. - **Alarm Symptoms (Red Flags)** — Clinical features such as unexplained GI bleeding, iron deficiency anemia, or persistent change in bowel habits that warrant prompt investigation for colorectal cancer. - **Colorectal Cancer** — A malignant neoplasm arising from the colon or rectum, often presenting with altered bowel habits, hematochezia, or melena in advanced stages. - **Bowel Habit Change** — A persistent alteration in frequency, consistency, or caliber of stools, which becomes clinically significant when lasting more than a few weeks. ## 같은 주제 문제 - [A nurse is assessing a 58-year-old client who was recently diagnosed with colorectal cance…](https://mymerci.kr/pages/nclex_q.php?qn_id=540726) - [A nurse is assessing a 58-year-old client who has been diagnosed with colorectal cancer. 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