Ileosigmoid knotting causing gangrenous bowel obstruction in a postpartal mother presented with septic shock: A case report and review of literature

Abstract

BACKGROUND

Ileosigmoid knotting, also referred to as compound volvulus, is a rare but potentially fatal cause of bowel obstruction. Only a limited number of cases have been reported since its first description. Prompt recognition and urgent surgical management are essential, as delayed diagnosis can lead to bowel gangrene, sepsis, and significant morbidity or mortality.

CASE SUMMARY

We report a 30-year-old para V lactating mother on her third postpartum day following an uneventful vaginal delivery. She presented with a three-day history of failure to pass feces and flatus, initially vomiting ingested matter that later became bilious, along with progressive abdominal distension. Her symptoms were preceded by initially mild, nonlocalized, crampy abdominal pain that gradually worsened over time. On admission, she was in shock, with unrecordable blood pressure and absent peripheral pulses. After insertion of two large-bore intravenous cannulas and aggressive fluid resuscitation, her hemodynamic status improved. Plain abdominal radiography suggested bowel obstruction. Emergency laparotomy revealed the sigmoid colon entrapped by the ileum. En bloc resection with rectal anastomosis and end ileostomy was performed. Relevant literature was reviewed to assess the diagnosis, management, and prognosis of ileosigmoid knotting.

CONCLUSION

Ileosigmoid knotting is an uncommon yet life-threatening cause of acute intestinal obstruction requiring a high index of suspicion. Rapid progression to bowel gangrene and septic shock necessitates early diagnosis, aggressive resuscitation, and prompt surgical intervention. Surgical management should be guided by bowel viability and hemodynamic stability, with stoma formation serving as a life-saving option in unstable patients. Early intervention and appropriate perioperative care can significantly improve outcomes.

Key Words: Ileosigmoid knotting; En block resection; Bowel obstruction; Laparotomy; Case report

Core Tip: Ileosigmoid knotting is a rare, life-threatening cause of intestinal obstruction, often presenting with nonspecific symptoms such as abdominal pain, distension, and vomiting. Diagnosis is challenging due to overlapping imaging features with sigmoid volvulus, and preoperative recognition is uncommon. Prompt aggressive resuscitation, correction of electrolyte and acid-base disturbances, and timely laparotomy are crucial. Surgical management depends on bowel viability, ranging from untwisting to en bloc resection with stoma formation. Early intervention, perioperative care, and close follow-up can significantly improve outcomes, even in patients presenting with shock and extensive bowel gangrene.

INTRODUCTION

Ileosigmoid knotting, sometimes referred to as compound volvulus or double volvulus, is a rare surgical emergency. Parker was the first to describe this condition in the literature in 1845[1]. Ileosigmoid knotting involves the encirclement of the sigmoid colon and its mesentery by the ileum, or vice versa[2]. It is crucial to distinguish ileosigmoid knotting from simple sigmoid volvulus, as endoscopic decompression in the former can be dangerous or even fatal; instrumentation may cause perforation or tissue injury during attempted decompression[3].

CASE PRESENTATION

Chief complaints

A 30-year-old black para 5 woman (all children alive) mother presented with a three-day history of failure to pass feces and flatus. In addition, she developed progressive abdominal distension over the preceding one day.

Immediately before the onset of progressive abdominal distension, she began experiencing mild, nonlocalized, crampy abdominal pain. However, she did not visit a health center, hoping the pain would resolve on its own. Over the following days, the pain progressively worsened and became severe.

She had delivered a healthy 3-kg male neonate via spontaneous vaginal delivery at a local health center three days prior to presentation, with no reported complications. All her previous deliveries were also vaginal.

Her current complaints began after she gave birth, following which she presented to our facility.

History of present illness

She reported two to three episodes of vomiting per day; initially, the vomitus consisted of ingested contents but later became bilious.

History of past illness

No known previous illness. She had no history of previous surgical procedures and denied any form of substance use or addictions.

Personal and family history

The patient denied personal or family illness in the past.

Physical examination

On arrival, she was in severe pain and appeared critically ill. She was severely dehydrated but remained fully conscious and oriented to time, place, and person.

The patient’s vital signs were as follows: Blood pressure was unrecordable; peripheral pulses were absent; carotid pulse rate was 160 beats per minute; and her extremities were cold. Her temperature was 36.0 °C, the patient’s respiratory rate was 18 breaths per minute, and oxygen saturation measured 90% on room air. Examination of the abdomen revealed gross distension with visible peristalsis in anterograde direction towards the rectum, but no tenderness. Upon auscultation, the bowel sounds were hyperactive, with a frequency of 36 gurgles per minute.

Digital rectal examination demonstrated normal anal tone and minimal fecal matter on the examining finger; no blood or mass was identified.

Laboratory examinations

Different investigations were performed, and the findings are summarized in Table 1.

Table 1 Laboratory results with reference ranges.

Test (classification)	Patient result	Standard normal range
Complete blood count - WBC	13 × 103/μL (neutrophils 60%, lymphocytes 34%)	(4-10) × 103/μL (neutrophils 40%-70%, lymphocytes 20%-40%)
Hemoglobin	15.5 g/dL	13.5-17.5 g/dL (male); 12.0-15.5 g/dL (female)
Hematocrit	45%	41%-53% (male); 36%-46% (female)
Platelet count	253 × 103/μL	(150-400) × 103/μL
Renal function - blood urea nitrogen	58 mg/dL	7-20 mg/dL
Renal function - serum creatinine	1.37 mg/dL	0.7-1.3 mg/dL (male); 0.6-1.1 mg/dL (female)
Liver enzymes - AST	50 U/L	10-40 U/L
Liver enzymes - ALT	19 U/L	7-56 U/L
Serum albumin	3.4 g/dL	3.5-5.0 g/dL
Serum electrolytes - sodium	135.3 mmol/L	135-145 mmol/L
Serum electrolytes - potassium	3.63 mmol/L	3.5-5.0 mmol/L
Serum electrolytes - calcium	2.3 mmol/L	2.1-2.6 mmol/L
Serum electrolytes - chloride	107 mmol/L	98-106 mmol/L

WBC: White blood cell; AST: Aspartate transaminase; ALT: Alanine aminotransferase.

Imaging examinations

A plain abdominal radiograph showed dilated peripheral bowel loops (Figure 1), suggestive of large bowel obstruction. Although a computed tomography (CT) scan was considered, it could not be performed due to lack of a functioning machine.

Figure 1  Peripherally dilated bowel loop suggesting large bowel obstruction.

FINAL DIAGNOSIS

Considering the clinical presentation of the patient, a diagnosis of septic shock of gastrointestinal focus and bowel obstruction secondary to ileosigmoid volvulus was made as final diagnosis.

TREATMENT

Considering the shock at presentation immediate resuscitative measures were initiated, and two intravenous lines were secured. The patient was started on aggressive intravenous fluid resuscitation. After administration of four liters of normal saline, her blood pressure improved to 95/65 mmHg, and her peripheral (radial) pulse rate decreased to 112 beats per minute.

A nasogastric tube was inserted for decompression. Intravenous antibiotics, including ceftriaxone 1 g and metronidazole 500 mg, were administered, and a urinary catheter was placed. After obtaining informed written consent, the patient was transferred to the operating room for laparotomy, during which around 3000 mL of hemorrhagic fluid was identified throughout the peritoneal cavity. The sigmoid colon was found to be entrapped by the ileum (Figure 2A). The entire length of the sigmoid colon was gangrenous (Figure 2B), and approximately 60 cm of the ileum, starting 5 cm proximal to the ileocecal valve, was also gangrenous. A 5-cm segment of the ileum, including the ileocecal valve, was viable, and the entire jejunum appeared normal. A thorough examination of the bowel and peritoneum was performed, and no mucosal polyps or masses were identified. The peritoneal fluid was sucked out. An en bloc resection with rectal anastomosis and end ileostomy was performed.

Figure 2 Laparotomy. A: Sigmoid colon (stars) entrapped by segment of ileum (arrow); B: Dilated, gangrenous sigmoid colon.

OUTCOME AND FOLLOW-UP

After the operation the patient exited the operating room with stable vital signs and was admitted to the post-anesthesia care unit for 12 hours. She was subsequently transferred to the recovery unit for continued close monitoring, where she remained under continuous observation for two days.

She was subsequently transferred to the ward, where wound care, stoma care training, and follow-up monitoring were provided. She remained hospitalized for a total of six days after surgery. Upon discharge, she and her family received education regarding stoma care, recognition of danger signs, nutrition, breastfeeding, and vaccination, and she was scheduled for stoma closure.

The patient presented on her scheduled date for stoma closure without any complaints. The stoma was successfully closed without complications. She remained hospitalized for five days postoperatively and was discharged with a follow-up appointment at the outpatient surgical clinic.

She was subsequently evaluated at the outpatient clinic at two, four, and eight weeks after discharge. At all follow-up visits, she reported no complaints and showed complete recovery. She was then formally discharged from the hospital.

DISCUSSION

Ileosigmoid knotting is a rare form of intestinal obstruction in which the ileum loops around the sigmoid colon and its mesentery. This condition may lead to gangrene of the ascending colon, caecum, and even the sigmoid colon. Although the exact prevalence of ileosigmoid knotting is unknown, it appears to occur more frequently among certain Asian, Middle Eastern, and African populations. Approximately 80% of affected patients are male, with a mean age at presentation of 40 years, ranging from 4 years to 99 years. However, the precise etiology remains unclear[4,5].

Theoretically, ileosigmoid knotting has been associated with several anatomical abnormalities, including a hypermobile small bowel, an elongated small-bowel mesentery, and a redundant sigmoid colon with a narrow mesenteric pedicle. In addition to these morphological factors, conditions such as Meckel’s diverticulitis with a fibrous band, ileocecal intussusception, a floating caecum, and transmesenteric herniation have been identified as potential risk factors for ileosigmoid knotting. A review of the literature suggests that the ingestion of a large meal following a period of small-bowel emptiness may precipitate ileosigmoid knotting, which may explain the higher incidence observed among Muslims during Ramadan. After a large meal, increased small-bowel peristalsis causes the heavier, food-filled segments of the jejunum to shift toward the left lower quadrant, allowing the empty jejunal and ileal loops to wrap around the narrower base of the sigmoid colon. Intraoperatively, this patient was found to have an elongated small-bowel mesentery and a redundant sigmoid colon with a narrow mesenteric pedicle[2,6-8]. The etiology of ileosigmoid knotting is influenced by three key factors. These include: (1) A long small-bowel mesentery with a highly mobile small intestine; (2) An elongated sigmoid colon with a slender mesenteric pedicle; and (3) Consumption of a large meal when the small bowel is empty. According to some studies, a large meal may progress into the proximal jejunum, where it enhances small-bowel peristalsis and gravitates toward the left lower quadrant of the abdomen[1,7,9].

The mobile small-bowel loops can then rotate around the tightly fixed sigmoid pedicle, and with increased peristalsis, this rotation may progress to a closed-loop intestinal obstruction. In addition to these primary mechanisms, several secondary factors have been implicated, these include late pregnancy, transmesenteric herniation, Meckel’s diverticulitis with an associated fibrous band, and ileocecal intussusception[10].

Ileosigmoid knotting can also occur during pregnancy, although it is rare. Approximately 15 cases of ileosigmoid knotting in pregnancy were reported between 1967 and 2025[11].

At the level of disease pathogenesis, physiological changes occurring during pregnancy can contribute to the development of intestinal obstruction. The slowing down of intestinal peristalsis and the increased tendency toward habitual constipation due to progestin influence lead to hypotonia of the intestinal smooth muscle[12].

Intestinal obstruction is most likely to occur during the second or third trimester of pregnancy and in the postpartum period[13].

Although our patient denied any history of constipation or neuropsychiatric disorders, she frequently consumed a high-fiber diet, as she is from northern Ethiopia, and her immediate postpartum state constituted the identifiable risk factors in this case.

The diagnosis of ileosigmoid knotting is challenging because its clinical presentation is nonspecific and overlaps with a broad range of differential diagnoses, including primary volvulus, hernias, adhesions, fibrous bands, intussusception, and other forms of intestinal knotting such as ileocecal, cecosigmoid, and ileo-ileal knotting. In the present case, the diagnosis was established intraoperatively. Appendicoileal knotting may also present with similar clinical features to ileosigmoid knotting[14].

Ileosigmoid knotting occurs more frequently in East Africa, though cases have also been reported in Asia, the Middle East, Northern and Eastern Europe, South America, and Turkey[11,15,16]. It predominantly affects males in their fourth decade of life[17]. A high-bulk diet in the context of an empty small bowel may act as a predisposing factor, which explains the higher incidence among Muslims who consume a single daily meal during Ramadan[18,19]. Ileosigmoid knotting in postpartal women described only in few literatures.

In addition to pregnancy, other risk factors include chronic constipation, sigmoid megadolichocolon, abnormal intestinal rotation, Hirschsprung’s disease, bowel adhesions, neuropsychiatric disorders (e.g., Parkinson’s disease, multiple sclerosis), and a high-fiber diet[15,20].

Two classification systems have been described for ileosigmoid knotting. The classification systems have described in Tables 2 and 3.

Table 2 Alver et al[19] classification (1993).

Type	Description	Frequency, %
Type I	Ileum (active component) wraps around the sigmoid colon (passive component). Type Ia - clockwise direction type Ib - anticlockwise direction	55
Type II	Sigmoid colon (active component) wraps around the ileum (passive component). Type IIa - clockwise direction type IIb - anticlockwise direction	25
Type III	Ileocecal segment (active component) wraps around the sigmoid colon (passive component)	5
Type IV	Undetermined - impossible to determine the revolved segment	15

Table 3 Atamanalp et al[20] classification (2009).

Class	Clinical criteria
Class 1	No risk factor
Class 2	No shock or gangrene but presence of other risk factors (e.g., age > 60 years or associated disease)
Class 3	Presence of shock
Class 4	Single-segment bowel gangrene (ileum or sigmoid colon)
Class 5	Shock and single-segment bowel gangrene
Class 6	Gangrene in both segments

The patient in our case was classified as having type II ileosigmoid knotting, as the ileum appeared to have twisted around the sigmoid colon[5,18].

Nevertheless, none of these classifications provide any details regarding the prognosis and available treatments for these illnesses[1].

In 2009, Atamanalp et al[20] introduced a new classification system based on preoperative and intraoperative criteria, which also correlates with mortality.

In our case, the patient had gangrene involving both the small bowel and the sigmoid colon; therefore, according to this classification, she was categorized as class 6[18].

The clinical presentation of ileosigmoid knotting is variable. Patients often present with hemodynamic instability, particularly when gangrene of one or both intestinal segments has developed. Patients commonly present with abdominal pain, sudden abdominal distension, and vomiting. Additional symptoms may include nausea, diarrhea, loss of appetite, rectal bleeding, and hematemesis. Physical examination typically reveals asymmetric abdominal distension and diffuse tenderness[19,21].

Additional clinical signs may include hyperactive bowel sounds, generalized tympany on percussion, rectal ballooning, and visible peristalsis[19,20]. Ileosigmoid can quickly lead to gangrene involving the ileum and/or sigmoid colon[20]. Without prompt treatment, patients may develop generalized peritonitis, sepsis, and severe dehydration, which can ultimately be fatal.

Despite the severity of the disease, preoperative diagnosis of ileosigmoid knotting remains challenging because of its nonspecific clinical presentation. This difficulty is further compounded in women of reproductive age, in whom the differential diagnosis of acute abdomen is particularly broad. Even with the availability of advanced imaging modalities, only a small proportion of patients are suspected of having ileosigmoid knotting preoperatively, largely due to the absence of pathognomonic imaging features. Therefore, maintaining a high index of clinical suspicion is crucial for the preoperative consideration of this condition[4,5,22].

Ileosigmoid knotting must be considered in patients who exhibit clinical signs of bowel obstruction but demonstrate radiologic features consistent with colonic obstruction[23]. Plain abdominal radiographs typically demonstrate a markedly dilated sigmoid colon accompanied by multiple small-bowel air-fluid levels. In cases complicated by perforation, free intraperitoneal air may be visible beneath the diaphragm[19,24]. In the present case, the plain abdominal radiograph was suggestive of large-bowel obstruction, as evidenced by peripherally dilated bowel loops.

Both clinically and on plain radiographs, it is commonly mistaken for sigmoid volvulus, and decompression with a sigmoidoscope or flatus tube typically fails to reduce the knot or relieve colonic distension[20].

Contrast-enhanced CT scanning with oral and rectal contrast can aid in the preoperative diagnosis of ileosigmoid knotting; however, as a result of its rarity, even CT imaging may fail to establish the correct diagnosis[25]. Additionally, contrast-enhanced CT is often unavailable in many institutions, particularly in emergency settings. CT findings suggestive of ileosigmoid knotting include the ‘whirl sign’, created by twisted intestinal loops and the sigmoid mesocolon, along with medial displacement of the cecum and descending colon[25,26]. Signs of bowel ischemia or gangrene resulting from strangulation may also be evident on CT imaging[27,28].

Although most clinical settings in developed countries have well-equipped emergency departments, including access to CT scans, which facilitate the diagnosis and consideration of ileosigmoid knotting, the diagnosis in developing countries is more challenging due to resource limitations and the absence of CT scanning in emergency settings.

Clinically and on plain radiographs, ileosigmoid knotting is frequently mistaken for sigmoid volvulus. In such cases, attempts to decompress the colon using a sigmoidoscope or flatus tube are usually ineffective and fail to relieve the obstruction caused by the ileosigmoid knot[21].

When an ileosigmoid knot is radiographically misinterpreted as simple sigmoid volvulus, endoscopic decompression via sigmoidoscopy may be attempted. However, perforation or injury may occur during endoscopic decompression of an ileosigmoid knot[24].

In the reported case, a CT scan was not performed due to the unavailability of a functional machine at the time. On flexible sigmoidoscopy, a spiral, sphincter-like mucosal twist may be observed within the sigmoid colon; however, this modality offers no assessment of the small intestine[27].

The overall rate of diagnostic accuracy was 20.8%, with abdominal radiography, CT, and magnetic resonance imaging (MRI) demonstrating diagnostic yields of 8.2%, 96.2%, and 100.0%, respectively[24].

In most resource-limited settings, the readily available imaging modality is abdominal X-ray; however, it is diagnostic in fewer than 10% of patients. The lack of advanced imaging modalities, such as CT and MRI, may lead to unnecessary and potentially dangerous interventions, such as sigmoidoscopy, resulting in complications including bowel injury, perforation, and sepsis.

In the reported case, sigmoidoscopy was not attempted because the patient was in shock at presentation.

Management of patients with ileosigmoid knotting should be initiated as early as possible. Priority should be given to nasogastric decompression and aggressive resuscitation with fluids and electrolytes, guided by central venous pressure monitoring or wide-bore intravenous access[19,24]. Correction of acid-base disturbances is particularly important, as vomiting may lead to hyponatremia and hypokalemia[19,24].

Exploratory laparotomy is the definitive treatment for ileosigmoid knotting and should not be delayed once the patient is hemodynamically stabilized[24]. Early administration of broad-spectrum antibiotics is essential and should be continued postoperatively. Typical regimens include combinations of cephalosporins or imipenem, aminoglycosides, and metronidazole[29].

The choice of surgical procedure depends on the viability of the involved intestinal loops. If both loops are viable, the knot may be carefully untwisted, which can be facilitated by a sigmoid enterotomy or needle puncture if necessary. However, when both the ileum and sigmoid colon are gangrenous, untwisting the knot carries a significant risk of spillage of toxic bowel contents, and surgical management should be planned accordingly[29].

To minimize contamination, before attempting detorsion or resection of the knot, intestinal clamps should be applied, with subsequent removal of any nonviable segments. Primary anastomosis may be undertaken if both bowel ends are viable and exhibit satisfactory perfusion[29].

While Hartmann’s procedure or a protective colostomy was historically recommended to reduce anastomotic leakage, current literature supports primary colonic anastomosis in selected cases with a short clinical course and well-vascularized, properly prepared bowel[29]. Specifically, primary anastomosis of a gangrenous sigmoid colon has been shown to be safe, without significant complications[30].

Primary anastomosis at a second-look laparotomy can be performed if both bowel ends are healthy, exhibit no gross contamination, possess adequate blood supply, and allow a tension-free anastomosis[30-32].

For patients with hypotension (< 90/60 mmHg) and tachycardia (> 120 beats/minute), either preoperatively or post-induction despite fluid resuscitation, urgent laparotomy is indicated. The approach typically involves en bloc resection of the diseased segment, closure of bowel ends, peritoneal lavage, and temporary abdominal closure[33].

To safeguard bowel stump viability, a stoma may be constructed[26]. Regardless of the extent of contamination, intraoperative colonic irrigation and thorough peritoneal lavage are mandatory[24].

In the reported case, the patient presented in shock, and after resuscitation and imaging evaluation, an urgent laparotomy was performed. En bloc resection of the affected segments, end ileostomy, and a descending colon-rectal anastomosis were carried out.

Reported mortality rates for ileosigmoid knotting vary widely, ranging from 2% to 55%, with a mean of approximately 36% across different studies[13,29,30,32]. Several prognostic factors have been identified, including the patient’s general condition, presence of shock, extent of bowel gangrene, and total duration of disease[8]. Morbidity is also high in these patients[8], with shock being the most common cause of death[27].

Second-look surgery or procedures involving stoma formation are associated with high survival rates, although they carry increased morbidity[27]. In the reported case, despite the patient presenting in shock and the presence of a large gangrenous bowel segment at laparotomy, early correction of shock, prompt initiation of antibiotics, and surgical management with stoma formation were crucial in achieving patient salvage.

CONCLUSION

Ileosigmoid knotting is an uncommon yet potentially life-threatening cause of intestinal obstruction that requires early recognition and prompt surgical intervention. Its nonspecific clinical presentation and overlapping imaging findings often delay diagnosis, making a high index of suspicion essential. Management focuses on aggressive resuscitation, correction of electrolyte and acid-base imbalances, and timely laparotomy. Surgical strategy depends on bowel viability, ranging from careful untwisting to en bloc resection with or without stoma formation. Despite high morbidity and variable mortality, early stabilization, appropriate antibiotics, and tailored surgical intervention can significantly improve outcomes, as demonstrated in the reported case.