Abdominal pain - Clinical Symptoms

Clinical Symptoms

Abdominal pain

The causes of abdominal pain are diverse, frequently involving inflammation, ischaemia and/or obstruction in different organs.

The characteristics of abdominal pain should be clearly defined when taking a history. A useful mnemonic is SOCRATES (Site, Onset, Character, Radiation, Alleviating factors, Timing, Exacerbating factors and Symptoms associated with the pain).

Site

Well-localised pain suggests involvement of the parietal peritoneum, which has somatic innervation. However, abdominal pain is often ‘referred’ pain due to the pattern of visceral innervation derived from the embryological development.

·        Disease of the embryonic foregut causes pain to be felt in the epigastrium or upper third of the abdomen. This includes the stomach, proximal duodenum (to the opening of the common bile duct), the liver, pancreas and biliary tree. The lower respiratory system and oesophagus are also derived from the foregut, so that occasionally abdominal pain can be due to disease in the chest.

·        Pain arising from the midgut, which continues down to two thirds of the way along the transverse colon, is felt in the paraumbilical region.

·        Pain arising from the hindgut, which continues to the dentate line, is felt in the suprapubic region.

Pain may begin in one area, then become localised as the peritoneum overlying the organ is involved, e.g. in appendicitis the pain is often initially felt around the umbilicus, then localises to the right iliac fossa.

Radiation

Pain radiating to the back is often due to retroperitoneal structures such as the pancreas, aorta and kidneys. If the disease is sub-diaphragmatic, then pain can be referred to the shouldertip because of innervation of the diaphragm by C4.

Onset, character and timing

Acute onset of pain suggests infarction, or an acute obstruction of the biliary tree or urinary tract. The pain may then last for hours. Other gastrointestinal pathology tends to cause a gradual onset of pain. The relationship of pain to posture, meals (including the type of food and timing of onset related to eating) and the pattern of severity should also be noted.

Obstruction of any part of the gut tends to cause ‘colicky’ pain, i.e. pain that comes in waves caused by contractions (peristalsis). Constant pain may be burning, dull, sharp, mild or severe. It may be recurrent, e.g. the nocturnal pain of peptic ulcer disease.

Alleviating and exacerbating factors

If movement exacerbates the pain, this is suggestive of peritoneal inflammation. Patients with colic tend to roll around in pain, whereas those with appendicitis lie absolutely still. Eating may relieve the pain of peptic ulceration, whereas it may precipitate the pain of ischaemia of the bowel. Vomiting or the passage of stool or flatus may temporarily relieve pain.