Mechanical Intestinal Obstruction: Causes, Clinical Features and Early Management Outcomes in Patients Operated at Iringa Regional Referral Hospital, Tanzania.

TA Karuhanga1*

1 St. Francis University College of Health and Allied Sciences, Ifakara, Morogoro, Tanzania

*Corresponding Author: TA Karuhanga, St. Francis University College of Health and Allied Sciences, Ifakara, Morogoro, Tanzania, TEL: (255) 23-2931-569; FAX: (255) 23-2931-569;

Citation: TA Karuhanga (2019) Mechanical Intestinal Obstruction: Causes, Clinical Features and Early Management Outcomes in Patients Operated at Iringa Regional Referral Hospital, Tanzania.. Medcina Intern 2019 3: 141

Copyright: :© 2019 TA Karuhanga, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Received date: December 26, 2019; Accepted date: December 29, 2019; Published date: December 31, 2019.


Background: Intestinal obstruction occurs when the normal flow of intraluminal contents is interrupted such that the peristalsis is working against an obstructing agent. It is one of the most recognized etiology of morbidity and mortality in surgical department all over the world. In Tanzania, like any other developing countries; mechanical bowel obstruction is common with scanty available data.

Objective: To determine the predictors of early management outcomes in patients with dynamic bowel obstruction who were operated at Iringa regional referral hospital, Tanzania.

Methodology: The study was carried out at Iringa Regional Referral Hospital (IRRH). Subjects: Patients who were diagnosed with intestinal obstruction and meeting the selection criteria between 1st October 2016 and 1st April 2017. The study was hospital-based prospective cross- sectional study. Purposive sampling method was used. Collected data were checked for any inconsistency, coded and entered into SPSS version 20.0 for data processing and analysis.

Result: Fifty nine patients who were diagnosed with intestinal obstruction were operated at IRRH. All patients were managed surgically. Sigmoid volvulus was the most cause of bowel obstruction.

Outcomes: Mortality rate was 6.8%. The most common complication was wound sepsis 15.3% and the overall morbidity was 18.6%.


Mechanical intestinal obstruction, management outcome.


Mechanical intestinal obstruction is the failure of passage of intestinal contents while the peristaltic movements are against an obstructing agent [13,19]. The obstruction may be high or low, if located to the small bowel it is small bowel obstruction (SBO) or large bowel obstruction (LBO) respectively [3]. It is a common global surgical emergency associated with a significant morbidity and mortality [7,10,11,19]. Intestinal obstruction contribute about 20% of general surgical emergency admissions in referral hospitals [7,13]. It remains an important part of surgical condition affecting all ages requiring immediate interventions [8].

The etiological factors of intestinal obstruction differ from one country to the other, but may differ even within the same country [13,17]. In developed countries where there are advanced surgical healthcare systems the leading cause of obstruction is adhesions (60%-80%) followed by Hernias, Crohn’s disease and neoplasms [3,7,17]. In Africa, the intestinal obstruction has been found to be the second surgical emergency hospital admission to trauma whereby hernia being the leading causes of intestinal obstruction in adults. In some areas of Africa, sigmoid volvulus has been found to be the leading cause of mechanical bowel obstruction in adults followed by external hernias [11]. In Tanzania, obstructed hernias account about 32.7% of mechanical bowel obstruction [13]. Currently, there is no study done on mechanical intestinal obstructions at IRRH. Therefore, the purpose of this study was to determine the prevalence, causes and clinical features of bowel obstruction at Iringa regional referral hospital and compare the findings that reported in other African countries.

Study setting and design

This was a hospital based cross-section study of patients operated for mechanical intestinal obstruction at Iringa Regional Referral Hospital (IRRH) from 1st October 2016 to 1st April 2017. IRRH is located in Iringa municipality in southern highlands of the United Republic of Tanzania. It is a regional referral and teaching hospital for the medical students of the University of Dodoma (UDOM). The hospital has 400 beds and provides a sub tertiary specialist care for a catchment population of approximately 9500 people from six districts of the region.

Study population and patients.

The patients with radiological and clinical evidence of mechanical intestinal obstruction admitted and operated at IRRH. But patients with co morbidity were excluded from the study. Patients who were managed conservatively, those with non-mechanical obstruction, who died before the operation and those with irreducible hernia were not involved in this study. Also patients who did not sign the consent and those who withdrawn from the study during the period of the study were excluded. All patients recruited into the study had intravenous fluids to correct fluid and electrolyte deficits, nasogastric suction (for decompression), nil per oral (NPO), urethral catheterization and broad-spectrum antibiotic preoperatively. Investigations done to all patients was blood grouping and cross-matching, hemoglobin level and plain abdominal X-ray (supine and erect). Abdominal ultrasound was also performed in some patients suspected to have peritonitis. Intraoperative tissue biopsy was taken in some patients for histopathological studies. After adequate resuscitation all patients under general anaesthesia had exploratory laparotomy after pre-operative anaesthetic assessment. The operations were performed either by a resident, registrar or by a consultant surgeon, the obstructing agent and bowel status were determined during operation and were documented. Post-operatively patients were kept nil orally till return of bowl sounds and at that time nasogastric tubes were removed depending on the volume of the nasogastric tube drainage. The postoperative outcome was monitored. If the patient developed one or more postoperative complications (including wound infection, anastomotic leakage, and developed septic shock) and/or death this was considered as unfavorable outcome of IO. The questionnaires were filled after the eventual outcome. The data were entered in Microsoft access at the end of each day for storage and backup. Patients were followed up until discharge or death.

Sampling methods

Consecutive enrollment technique was conducted such that the subjects meeting criteria were enrolled, all patients were sorted first by admitting doctor at outpatient department (OPD). Also some of the patients were identified during daily ward round. Other patients were identified from other wards on surgical consultation. A structured questionnaire was developed to collect important information including age, sex, duration of the illness, clinical presentations, clinical features, intraoperative findings, intra-operative procedures, causes of IO, postoperative complications and management outcome. Data collection, two residents were recruited to help in data collection. The Principal Investigator monitored and oversaw the daily activities of data collection.

Data Analysis

Data were analyzed by using SPSS version 20. Multivariate analysis was done to isolate the independent predictor of management outcome of intestinal obstruction. Statistical significance was based on p-value of <0.05 with a confidence interval of 95%. A 5% level of significance was used through the study an independent variable with p- value less than 0.05 was considered as significantly associated with outcome variable.

Ethical Consideration.

Before initiation of this study the proposal was submitted to the University of Dodoma for approval by the Institutional Research and Ethics Committee of the University. Informed consent to conduct the study was sought in writing directly from adult patients. All participants were free to participate in the study willingly or to withdraw from it during the study progress. Information gathered was confidential and used only for the purpose of this study.


Socio-Demographic characteristics

A total of 59 patients were involved in the study for the period of six months. Age ranged from 17-70 years. There were Males 45 (76.3%) and 14 (23.7%) females. The most vulnerable age group was 31 to 50 and the age group with least patients was 51 to70. The patients from rural areas were 35 (59.3%), while 24 (40.7%) patients were from urban areas. Among the participants, 12 (20.3 %) had no education, 66.1 % (39) patients had primary education and 4 (6.8%) patients had Secondary education while 4 (6.8%) patients had higher education. Most of the patients were peasants 43 (72.9%), only 7 (11.9 %) patients were employed and 2(3.4%) patients were students as shown in Table 1 below.

Table 1: Demographic Characteristics of studied population.

Variable Frequency Percent %
Age group
10-30 yrs 16 27.1
31-50 yrs 31 52.1
51-70 yrs 12 20.3
Male 45 76.3
Female 14 23.7
Rural 35 59.3
Urban 24 40.7
Peasants 43 72.9
Employed 7 11.9
Students 2 3.4
Business 7 11.9

Clinical presentation and abdominal X-ray features.

Out of 59 patients who were enrolled, 58 (98.3%) patients presented with colicky abdominal pain, 54 (91.5%) patients had a history of vomiting, and 53 (89.8%) patients had history of abdominal distension, 53 (89.8%) patients had history of constipation as shown in Table 2.

Table 2: Distribution of the Patients According to the Clinical Features, in Patients with IO operated at IRRH.

Variable Frequency Percent %
Colicky abdominal pain
Yes 58 98.3
No 1 1.7
Yes 54 91.5
No 5 8.5
Abdominal distension
Yes 53 89.8
No 6 10.1
Yes 53 89.8
No 6 10.1

Causes of Intestinal Obstruction, Surgical Treatment and the Outcomes

A total of 33 (55.9%) patients had sigmoid volvulus (among these, 27.3% had strangulated gangrenous bowel as shown in (Figure 1), 3 (9.1%) had Ileo-Sigmoid (I-S) knotting, 22 (37.3%) had adhesion, 2 (3.4%) had Internal inguinal hernia and 3 (5.1%) had colonic tumors. All 59 patients had surgical intervention (laparotomy), adhesiolysis was done in 16 (27.1%), resection and primary anastomosis was done in 35 (59.3%), colostomy in 2 (3.4%) patients, 1 (1.7%) patient had Iliestomy, and 2 (3.4%) patients, untying of ileo-sigmoid knotting were done while bowel reduction were done in the two (3.4%) patients who had internal hernia. Out of 59 patients, 55 (93.2%) survived while 4 (6.8%) died, the cause of deaths were septic shock in all deaths. Among the survivors, 9 (15.3%) patients developed wound infection, two (3.4%) patients developed enterocutanous fistula formation as shown in (Table 3). The duration of hospital stay ranged from 4 to 28 days. The mean duration of stay was 8days.

Figure 1
Figure 1: Gangrenous and Grossly Dilated Sigmoid Volvulus of one of the operated patients (Arrow).

Table 3: Distribution of the Patients According to the Etiology, Surgical Procedure and the Outcomes.

Variable Frequency Percent %
Volvulus with or without I-S Knotting 33 55.9
Adhesion 22 37.3
Hernia 2 3.4
Tumor 3 5.1
Surgical management
Adhesiolysis 16 27.1
RPA 35 59.3
Colostomy/eliostomy 3 5.1
Reduction/unknotting 4 6.8
No complication. 44 74.6
Wound infection. 9 15.3
Enterocutaneous fistulae. 2 3.4
Death 4 6.8


Mechanical intestinal obstruction is one of the commonest global life threatening abdominal emergencies with no specific age exclusion. In this study, the most affected age group was the third to fifth decades with the males outnumbering the females by 76.3%. The similar findings have been reported in other studies [13,17,19]. The study differs from that conducted by Deshmukh et al (2016) in which the highest frequency was in 51 to 60 year group. The cause of the variation may be due to etiological agent such as obstructed inguinal hernia which is more common in adults who are in the age of fifties.

The classical features of IO in this study were colicky abdominal pain, vomiting, abdominal distension and absolute constipation. Colicky abdominal pain was the most common with frequency of 98.3%. Vomiting was 91.5%, while abdominal distension occurred in 89.8% and constipation 89.8% patients respectively. These findings are consistent with other studies [2,13,16] but the study differ from Atif Sharif et al (2015) whose study reported 84% of abdominal distension, bilious vomiting 66%, absolute constipation 76% and abdominal pain 70% [4]. These variations may be attributed by etiological agent, site of bowel obstructed and duration of the illness [13].

In this study, sigmoid volvulus was the commonest cause of intestinal obstruction constituting 55.9% of the total patients out of these 9.1% had compound volvulus (Ileo-sigmoid knotting). The study is consistence with the study done in Parkistan by Mumtaz Safir Ullah et al (2009) who reported sigmoid volvulus to be the most bowel obstructing agent by 20.83% followed by large bowel tumor 10. 45% [15]. Sigmoid volvulus remains the major cause of large bowel obstruction reported in various literatures especially in the areas known as “sigmoid volvulus belt”. The risk factors are high fibers food and elderly people. The relation of sigmoid volvulus to high altitude is reported in the literature with limited scientific evidence on its pathophysiology. It is thought that, there is an increase of intraluminal pressure in these population while the mechanism is unclear [12]. Iringa is a highland region having the similar characteristics of “Sigmoid volvulus Belt”. This study was conducted in semi urban tertiary hospital (Iringa Referral region), where the main diet of inhabitants includes maize, rice, beans, millet, cassava and green vegetables. These two factors (high altitude area and high fibers diet) may be regarded as the main contributing factors to high prevalence of sigmoid volvulus in this study. However, the study differ from other studies in African countries in which most of them report inguinal hernia to be the most leading cause of bowel obstruction [6,13] followed by adhesion [11,17] while in this study inguinal hernia was the least obstructing agent. This could be due to the population awareness upon inguinal hernia as a result herniorrhaphy is done as an elective procedure.

Emergency surgical management is known to be the treatment of choice for patients with mechanical intestinal obstruction [13]. All patients involved in this study underwent surgical intervention. The major intraoperative procedure was bowel resection and primary anastomosis, 59.3% patients underwent resection and primary anastomosis, These findings become similar to those which have been reported in other literatures [1,5,9,14,17,18]. The study differ from other studies which advocate Hartman procedure (bowel resection and primary anastomosis) used in ischemic and gangrene sigmoid volvulus is associated with significant morbidity and mortality [18]. Recently, the one stage procedure without colostomy has shown to be associated with low morbidity and less costable [14]. This procedure has been reported in Kenya by Kuremu et al (2008) who found low morbidity of 3.3% [9].

The most common complication in this study was wound sepsis which accounted 15.3% of the total patients while 3.4% developed colocutaneous fistula formation. Similar findings have been reported in several studies worldwide [5,15,17]. Possible factor for wound sepsis may be due to bowel strangulation with bacterial translocation at the time of surgery [7]. Despite the fact that, antibiotics were administered before and after operation still wound sepsis occurred, this could be explained that may be the antibiotics used were less sensitive to infectious agents.

Out of 59 patients the mortality rate was 6.8%. It is one of the lowest mortality rates that have been reported in Africa and Tanzania as well [6,11,13]. However, this mortality rate is higher than that in Ethiopia by Abebe Urgessa et al (2016) who reported mortality rate of 2.5 % [19].


The study demonstrates that the pattern of dynamic bowel obstruction differs from the Western world with obstructed hernias being the most important cause in this region and contributes significantly to high morbidity and mortality. The outcome of bowel resection and primary anastomosis was of acceptably low (morbidity and mortality 18.6% and 6.8% respectively) in comparison to other global outcomes. The possible reason for fair outcomes could be the absence of co-mobidities (diabetic mellitus, cardiovascular diseases and extreme ages) which are believable to be the contributing factors of poor outcomes. It is therefore recommended that, emergency resection and primary anastomosis for the patients without high risk factors such as advanced age and co-morbidity. Cases with gangrene must be treated by emergency resection followed by either primary anastomosis or colostomy to allow the maximum optimization for favorable outcome.


The author would like to thank the Vice Chancellor of the University of Dodoma (UDOM), Head of Department of Surgery, UDOM, Medical Officer in charge of Iringa regional referral hospital and Dr Masumbuko Mwashambwa my MMED program supervisor. Also my I would like to convey my gratitude to Missenyi District Executive Director (DED) for granting me the study leave. Lastly, I would like to give thanks to my family for social and financial support.


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