# Situation: A 32-year-old woman with ulcerative colitis is admitted for a flare. She has 8 bloody stools a day, a temperature of 38.2 °C, a heart rate of 104/min, and a hemoglobin of 9.8 g/dL (98 g/L). Stool tests for Clostridioides difficile and other pathogens are pending. The nurse compares her assessments (normal serum potassium 3.5–5.0 mEq/L): Day 2 — 8 bloody stools in 24 hours, abdomen soft, temperature 38.2 °C, heart rate 104/min, serum potassium 3.4 mEq/L Day 4 — 2 stools in 24 hours, abdomen distended and tender, temperature 39.0 °C, heart rate 126/min, serum potassium 3.1 mEq/L What should the nurse suspect on day 4?

> source: MyMerci (mymerci.kr)  
> url: https://mymerci.kr/pages/nclex_q.php?qn_id=629822  
> language: ko  
> subject: Nursing Practice III — Care of Clients with Problems in Surgery, Oxygenation, Fluid and Electrolytes, Infectious, Inflammatory and Immunologic Response, Cellular Aberrations

## 문제

Situation: A 32-year-old woman with ulcerative colitis is admitted for a flare. She has 8 bloody stools a day, a temperature of 38.2 °C, a heart rate of 104/min, and a hemoglobin of 9.8 g/dL (98 g/L). Stool tests for Clostridioides difficile and other pathogens are pending.

The nurse compares her assessments (normal serum potassium 3.5–5.0 mEq/L):
Day 2 — 8 bloody stools in 24 hours, abdomen soft, temperature 38.2 °C, heart rate 104/min, serum potassium 3.4 mEq/L
Day 4 — 2 stools in 24 hours, abdomen distended and tender, temperature 39.0 °C, heart rate 126/min, serum potassium 3.1 mEq/L
What should the nurse suspect on day 4?

## 보기

1. Improvement in response to treatment
2. Constipation from reduced food intake
3. Toxic megacolon from severe colitis **✔ 정답**
4. Paralytic ileus from low potassium

**정답: 3**

## 해설

A sudden fall in stool frequency together with abdominal distension, rising fever, and worsening tachycardia is the warning pattern of toxic megacolon, a life-threatening complication of severe colitis. Low potassium can contribute to colonic dilation, but it does not explain the rising fever and heart rate, which show systemic toxicity. Fewer stools here reflect loss of colonic motility, not healing; the nurse reports at once, and an abdominal X-ray showing colonic dilation confirms it.

## 심화 해설

Clinical picture on day 4
The change from 8 bloody stools to only 2 stools in 24 hours may superficially look like improvement, but it is accompanied by new abdominal distension and tenderness, a higher fever (39.0 °C), and a faster heart rate (126/min). This combination is the classic warning pattern of toxic megacolon, a life-threatening complication of severe ulcerative colitis. A falling stool count in this context reflects loss of colonic motility and impending colonic dilation, not mucosal healing.

Why the other options do not fit
Option 1, improvement, is contradicted by the worsening vital signs and new abdominal findings. Option 2, constipation from reduced food intake, does not explain fever, tachycardia, or a tender, distended abdomen. Option 4, paralytic ileus from low potassium, is a tempting distractor because the potassium is falling (3.1 mEq/L). Hypokalemia can contribute to colonic dilation, but it does not account for the rising fever and heart rate, which point to systemic toxicity. In toxic megacolon, the inflammatory process itself drives the clinical deterioration; potassium abnormalities are a secondary or aggravating factor, not the primary explanation.

Pathophysiology and clinical recognition
In severe colitis, transmural inflammation impairs smooth muscle contractility and disrupts the normal neuromuscular coordination of the colon. As inflammation extends deeper, the colon loses its ability to propel contents forward. The lumen progressively dilates, and the patient may pass fewer stools even though the disease is worsening. Abdominal distension, tenderness, fever, and tachycardia together signal systemic toxicity and impending or established colonic dilation. The reported case in the supporting literature describes a patient with severe ulcerative colitis whose course was marked by abrupt septic shock and acute colonic dilatation on imaging, underscoring that toxic megacolon is a medical and surgical emergency with a poor prognosis if unrecognized [1].

Comparison of day 2 and day 4 findings

| Assessment | Day 2 | Day 4 | Clinical meaning |
| --- | --- | --- | --- |
| Stool frequency | 8 bloody stools | 2 stools | Decreased motility, not healing |
| Abdomen | Soft | Distended and tender | Colonic dilation and inflammation |
| Temperature | 38.2 °C | 39.0 °C | Worsening systemic toxicity |
| Heart rate | 104/min | 126/min | Compensatory response to sepsis or hypovolemia |
| Serum potassium | 3.4 mEq/L | 3.1 mEq/L | Contributing factor to ileus, not primary cause |

Nursing implications
Watch out! A sudden drop in stool output in a patient with severe colitis is not a sign of recovery when it occurs with abdominal distension, tenderness, and worsening vital signs. Key point! Toxic megacolon is a clinical diagnosis suspected at the bedside; an abdominal X-ray showing colonic dilation confirms it. The nurse must report these findings immediately because early recognition and treatment are crucial to reduce morbidity and mortality . Inflammatory bowel disease, particularly ulcerative colitis, is the most common underlying condition associated with toxic megacolon, although infectious etiologies such as Clostridioides difficile must also be considered while stool tests are pending . Conservative management requires close interdisciplinary care and intensive monitoring, but the first nursing action is prompt recognition and escalation .
References (research sources)

- [1]A rare and severe case of toxic megacolon: Radiological emergency.Research articleAbddaimi S, Benramdane H, Boubacar A, Ziani H, Nasri S, Kamaoui I, Skiker I. (2026) · DOI: 10.1016/j.radcr.2026.03.003

## 임상 시나리오

Toxic Megacolon Recognition in UC FlareWhen fewer stools mean danger, not recovery
A sudden drop in stool frequency with abdominal distension, rising fever, and worsening tachycardia is the warning pattern of toxic megacolon. Fewer stools reflect loss of colonic motility, not mucosal healing.

In severe colitis, transmural inflammation impairs smooth muscle contractility and neuromuscular coordination. As inflammation extends deeper, the colon loses its ability to propel contents, and the lumen progressively dilates.

CautionReport immediately and anticipate an abdominal X-ray to confirm colonic dilation. Hypokalemia (3.1 mEq/L) may aggravate dilation but does not explain the fever (39.0 °C) or heart rate (126/min)—these indicate systemic toxicity.

## 핵심 개념

- **Toxic megacolon** — Life-threatening complication of severe colitis characterized by colonic dilation and systemic toxicity, presenting with decreased stools, abdominal distension, fever, and tachycardia.
- **Ulcerative colitis** — Chronic inflammatory bowel disease affecting the colon, with flares causing bloody diarrhea and systemic symptoms.
- **Hypokalemia** — Low serum potassium (
- **Transmural inflammation** — Inflammation extending through all layers of the bowel wall, impairing motility and neuromuscular coordination.
- **Systemic toxicity** — Clinical signs of widespread inflammation including fever, tachycardia, and hemodynamic instability.

## 같은 주제 문제

- [Situation: A 29-year-old woman has a pre-employment medical examination at a private manuf…](https://mymerci.kr/pages/nclex_q.php?qn_id=629716)
- [Situation: A 29-year-old woman has a pre-employment medical examination at a private manuf…](https://mymerci.kr/pages/nclex_q.php?qn_id=629717)
- [Situation: A 29-year-old woman has a pre-employment medical examination at a private manuf…](https://mymerci.kr/pages/nclex_q.php?qn_id=629718)
- [Situation: A 29-year-old woman has a pre-employment medical examination at a private manuf…](https://mymerci.kr/pages/nclex_q.php?qn_id=629719)
- [Situation: A 34-year-old man was diagnosed with human immunodeficiency virus (HIV) infecti…](https://mymerci.kr/pages/nclex_q.php?qn_id=629720)
- [Situation: A 34-year-old man was diagnosed with human immunodeficiency virus (HIV) infecti…](https://mymerci.kr/pages/nclex_q.php?qn_id=629721)
- [Situation: A 34-year-old man was diagnosed with human immunodeficiency virus (HIV) infecti…](https://mymerci.kr/pages/nclex_q.php?qn_id=629722)
- [Situation: A 41-year-old man is admitted to the medical ward with weakness that began in b…](https://mymerci.kr/pages/nclex_q.php?qn_id=629723)

---

More free questions: [기출문제](https://mymerci.kr/)

_학습 참고용입니다. 실제 임상은 최신 지침과 소속 기관 프로토콜을 따르세요._