Left Iliac Fossa Pain

The general articles: abdominal pain, abdominal examination and pelvic pain have some overlap with this article.

Left iliac fossa (LIF) pain may occur due to a self-limiting condition but may also be a sign of a medical/surgical emergency. It is less common than RIF pain. The two share a considerable number of differential diagnoses but some conditions are more likely, or only likely, on one side. LIF pain is common and tends to affect an older population than RIF pain.

Parietal pain occurs when there is noxious stimulation of the parietal peritoneum because of ischaemia, inflammation or stretching. It is sharp, intense, discrete, localized and aggravated by coughing/movement. Visceral pain occurs when noxious stimuli affect a viscus. Hindgut structures (e.g. large intestine) cause lower abdominal pain. Referred pain is pain felt in remote areas supplied by the same dermatome as the diseased organ.¹

• Enquire about the pain:
  • Point to where it is. Does the patient use a single finger or is it more diffuse?
  • When did it start? Acute abdominal pain is generally pain that has been present for < 1 week.²
  • Was the onset sudden or gradual?
  • Is it continuous or intermittent?
  • Describe the nature of the pain, stabbing, burning, gripping etc.
  • Aggravating or relieving factors, e.g. food, position, medication? Parietal pain is aggravated by movement. Relief of pain after a bowel movement suggests a colonic cause. Relief after vomiting suggests a cause in the more proximal bowel.
  • Radiation, e.g. back/groin (renal colic), shoulder (diaphragmatic irritation secondary to visceral perforation)?
• Make a systematic enquiry:
  • Appetite, any nausea or vomiting?
  • Fever symptoms?
  • Weight - stable? Any weight loss (probably more relevant in chronic LIF pain when considering colorectal carcinoma)?
  • Bowels - when were they last open? Ability to pass stool/flatus? Any blood, mucus, malaena? Consistency of stool?
  • LMP, menstrual history, irregular vaginal bleeding and form of contraception?
  • Vaginal discharge?
  • Urine - are any urinary symptoms present?
  • Smoking and drinking history?
• Note past medical history
• Medication

• Note the general condition of the patient, e.g. well, shocked, pyrexial.
• Note temperature, pulse rate and quality, BP.
• With the patient adequately undressed and comfortable, systematically examine the abdomen - inspection, percussion (abdomen may be tympanitic in bowel obstruction), palpation, auscultation (absent bowel sounds indicate obstruction/volvulus). Is it an acute abdomen - is there distension, guarding, rigidity or rebound tenderness? Is a mass palpable, and if so, is it pulsatile?
• Examine testes and hernial orifices.
• A definitive diagnosis may well require a rectal and/or vaginal examination. Usually a GP will do this only if it affects the decision of whether or not to refer the patient acutely. If it will be performed by the admitting team, it may be omitted.

These should be tailored to the patient's symptoms and the examination findings. In the GP setting there are a number of bedside tests that can be done to aid diagnosis:

• Dip urine for pus cells, leucocytes and/or nitrites if UTI suspected. Microscopic haematuria is usually present in ureteric colic. It can also occur in abdominal aortic aneurysm (AAA).³
• Perform a pregnancy test if ectopic pregnancy or miscarriage suspected.

If the pain is non-acute and can be managed in the GP setting, further investigations may be requested:

• Blood tests may include full blood count, renal function, liver function tests.
• Vaginal swab tests can help to exclude pelvic infection.
• Ultrasound scanning can show ovarian or other mass.
• Referral for further bowel investigations may be necessary, e.g. referral under 2 week wait rule if bowel carcinoma suspected.
• Further urological investigations may be needed, e.g. cystourethroscopy.

If the patient has an acute abdomen and is referred immediately to hospital, further diagnostic tests may be carried out:

• Ultrasound scanning, blood and swab tests as above.
• CT scanning is good for the diagnosis of diverticulitis, nephrolithiasis, ureterolithiasis.³
• Plain AXR may show dilated bowel loops in bowel obstruction, ileus and perforation. It may show renal tract calcification.
• Erect CXR may show intraperitoneal air under the diaphragm if there is a ruptured viscerus.

LIF pain may be acute or chronic/subacute.

Causes of acute LIF pain

Gastrointestinal causes

• Gastroenteritis: however, this commonly causes more generalised abdominal pain. It is the commonest cause of abdominal pain in children with viral causes being most frequent. Care should be taken as gastroenteritis specifically causing LIF pain should be a diagnosis of exclusion.
• Constipation: acute constipation usually has an organic cause (e.g. gastroenteritis).¹ Again, it should be a diagnosis of exclusion.
• Diverticulitis: over 90% of diverticular disease involves the sigmoid colon and therefore diverticulitis most commonly presents with LIF pain.⁴
• Volvulus: sigmoid volvulus is the most common type of colonic volvulus.⁵ It can lead to large bowel obstruction and can have an insidious onset in elderly patients.
• Left inguinal/femoral hernia: an incarcerated left inguinal or femoral hernia may present as LIF pain. There will be tenderness and an irreducible swelling over the hernial orifice and symptoms and signs of bowel obstruction. Cough impulse is lost if hernia is incarcerated. Requires urgent surgical referral.

Gynaecological causes

• Ectopic pregnancy in the left fallopian tube: pain rather than vaginal bleeding is the prominent feature. If in doubt, admit. When rupture occurs bleeding is profuse and 2 or 3 litres can be lost in a short space of time with consequent hypovolaemic shock.
• Threatened or complete abortion: if pregnancy test is positive and there is a history of bleeding, always refer for an ultrasound scan to exclude an abortion. If there is associated pain, an ectopic needs excluding by immediate referral to secondary care.
• Causes of LIF pain in later pregnancy: premature labour, placental abruption, uterine rupture.
• Pelvic inflammatory disease/salpingitis/pelvic abscess: typically vaginal discharge is present. More common if multiple sexual partners, history of PID and if intrauterine device in situ.
• Mittelschmerz: this is a sudden onset of mid-cycle pain.
• Ovarian torsion: this usually happens when an ovary is enlarged by a cyst. Diagnosis can be difficult. There may be adnexal tenderness. Ultrasound may show the abnormal ovary.
• Fibroid degeneration
• Pelvic tumour

Urological causes

• Testicular torsion or epididymo-orchitis: may produce pain that is referred to the lower abdomen on that side. The testis will be very tender.
• Ureteric colic: this can cause pain that may be intermittent and "shooting". A stone may cause microscopic haematuria. 70% are visible on plain x-ray. Ultrasound is a good diagnostic technique.
• UTI: urinary frequency, dysuria, haematuria, urgency and smelly urine may raise this as a differential diagnosis.

Other causes

• Abdominal aortic aneurysm: this can present with atypical symptoms resembling renal colic or diverticular disease rather than the classic back or flank pain. Do not forget this differential diagnosis. Look for a pulsatile abdominal mass.⁶ Approximately 30% of patients with a ruptured AAA are misdiagnosed initially.³
• Situs inversus: here, the differential diagnosis for LIF pain is that for RIF pain (refer to separate article entitled 'Right Iliac Fossa Pain'. Only half of those with dextrocardia have total situs inversus.
• Herpes zoster: usually a characteristic rash. Before rash appears the skin can be tender.
• Pelvic vein thrombosis

Causes of chronic LIF pain

Gastrointestinal causes

• Constipation: chronic constipation usually has a functional cause (e.g. low-residue diet). Pain related to it is most often left-sided or suprapubic.¹
• Irritable bowel syndrome: should be a diagnosis of exclusion. The bowel may be loaded and tender.
• Carcinoma of rectum or descending colon: there is usually an associated change in bowel habit, weight loss and rectal bleeding. It may present with obstruction and perforation.
• Crohn’s disease and ulcerative colitis: inflammatory bowel disease can affect the distal colon. There will probably be diarrhoea with blood and mucus.

Gynaecological causes

• Ovarian/pelvic tumour
• Endometriosis

Other causes

• Hip pathology

• Management depends on diagnosis and is of the underlying disorder.
• An acute abdomen and/or a haemodynamically unstable patient requires immediate referral to hospital for further assessment. If AAA or ectopic pregnancy are suspected, refer to secondary care immediately. Keep patient nil by mouth.
• Airway, Breathing and Circulation should be assessed and managed appropriately.
• Traditional teaching was that analgesia shouldn't be given to patients with an acute abdomen before they see a surgeon as it can suppress physical signs. This has been subject to much debate and modern opinion is that it is unkind and unnecessary to withhold pain relief.⁷ The receiving doctor should be told that analgesia has been given. A Cochrane systematic review published in 2007 provided some evidence to support the notion that the use of opioid analgesics in patients with abdominal pain is helpful in terms of patient comfort and doesn't retard decisions to treat.⁸
• NSAIDs (care if risk of peptic ulcer disease) or opioids (if severe pain) are good analgesics.