TOPICS OF INTEREST

Some aspects of abdominal pain

Visceral and non-visceral pain

Pain arising from internal organs is called visceral pain. This differs from non-visceral, or somatic pain, which arises from muscles, nerves or joints. Visceral pain tends to last for minutes to hours, and can be steady or colicky (coming in waves). Visceral pain is not well localised to the organ it arises from. For example, pain felt in the upper middle part of the abdomen, called the epigastrium, can arise from any of a number of internal organs including the oesophagus, stomach, duodenum, the gallbladder or the pancreas(1). The gallbladder is in the right side of the abdomen, but pain from gallstones (biliary colic) is most commonly felt in the midline, although sometimes it is felt in the right side, and very rarely on the left. Although the stomach is on the left side of the abdomen and the duodenum on the right, pain from gastric and duodenal ulcers are almost always felt in the midline (1). Pain from the intestines eg due to irritable bowel syndrome tends to be in the lower abdomen or around the umbilicus, in the midline. Depending on which organ it arises from, visceral pain is often made worse or relieved by bodily functions eg swallowing, eating, passing flatus or opening the bowels.

Non-visceral pain, in contrast, can sometimes be continuous, day and night or whenever the patient thinks about it. Musculo-skeletal type pain is often exacerbated or relieved by stretching, straining, movement or change in position. Momentary stabbing pains may be nerve pains. Non-visceral pain is not normally due to serious disease. Sometimes the exact origin of musculo-skeletal pain can be determined, if pressure on a bone or ligament makes the same pain worse. A common example is the ‘painful rib syndrome’(2), in which what seems to be upper abdominal pain actually arises from the rib cage or the lower end of the sternum (breast bone). The pain can be reproduced by pressing on a particular trigger point over the rib cage. This condition can be considered as a form of rheumatism, and many patients find the pain does not bother them very much once they understand it is not due to serious disease.

Radiation of pain

Abdominal pain is sometimes also felt in the back (radiated pain). Whether a pain radiates to the back or not does not help very much in determining where the pain arises from, although pain from some organs eg the gallbladder or pancreas, are more likely to do so than other kinds of pain(1).

What makes the pain better or worse

Precipitating and relieving factors sometimes suggest where the pain arises from. For example pain from the gullet (oesophagus), the stomach and the duodenum is often related to acid in the stomach, and is therefore brought on or improved by food and drink. The pain of peptic ulcer is typically brought on by hunger while the pain of functional dyspepsia (gastric pain not due to ulcer or oesophagitis) is typically worse after food. Pain from gallstones is often brought on by eating greasy food. Pain in the chest as food is swallowed may arise from the oesophagus (gullet) and may be associated with heartburn and difficulty in swallowing. Pain arising from the intestines eg from irritable bowel syndrome, may give an urge to pass wind or to move the bowels and may be relieved by defecation or passing flatus.

Pain from peptic ulcer and functional dyspepsia is in part caused by the presence of acid produced by the stomach(3), and is therefore relieved by antacids eg Gaviscon, or medicines which suppress acid secretion in the stomach eg ranitidine, lansoprazole.

Some causes of abdominal pain

Peptic ulcer, which can be gastric or duodenal, typically gives rise to a burning or dull upper abdominal pain which can be worse when hungry and be relieved by food. This pain sometimes wakes the patient from sleep(4). Peptic ulcer is usually caused by the use of aspirin or other anti-inflammatory drugs eg ibuprofen, or due to infection with a germ called Helicobacter pylori (H pylori).

Functional dyspepsia is pain arising from the stomach, without peptic ulcer or other structural disease being present. Typically it is worse after food. In a small proportion of cases the pain is due to H pylori infection, and can be cured if the infection is eradicated. However, in most patients with H pylori infection and functional dyspepsia, the infection does not cause the abdominal pain and hence treatment of the infection will not make the pain better.

Gastro-oesophageal reflux disease typically gives rise to heartburn (a burning sensation behind the breast bone, which sometimes rises) but often there is upper abdominal pain as well. Patients also get regurgitation and excessive belching. Symptoms of gastro-oesophageal reflux are typically worse after food or drink, upon bending over and lying down. Heartburn in a patient with gastro-oesophageal reflux is not caused by H pylori infection and hence treatment of the infection does not usually make any difference to the symptoms.

The pain from irritable bowel syndrome is typically lower abdominal or generalised but can occasionally be upper abdominal. Typically, this pain gives rise to an urge to pass wind or open the bowels and is then relieved. There is often abdominal bloating and the onset of pain often coincides with the occurrence of diarrhoea or constipation.

References:

  1. Kang J Y, Tay H H, Guan R. Chronic upper abdominal pain: site and radiation in various structural and functional disorders, and the effect of various foods. Gut 1992 ; 33 : 743-8
  2. Scott EM. Scott BB. Painful rib syndrome-a review of 76 cases. Gut. 1993; 34;1006-8,
  3. Kang J Y, Yap I, Guan R, Tay H H. Acid perfusion of duodenal ulcer craters and ulcer pain - a controlled double-blind study. Gut 1986; 27: 942-5.
  4. Kang J Y, Ho K Y, Yeoh K G, Guan R. Chronic upper abdominal pain due to duodenal ulcer and other structural and functional causes: its localisation and nocturnal occurrence. Journal of Gastroenterology and Hepatology 1996: 11: 515-9.

The effect of chilli on gastrointestinal symptoms and diseases

Chilli and abdominal pain

Many people find that chilli or spicy food cause abdominal pain, or make pre-existing pain worse. Many patients therefore avoid the use of chilli, either through personal experience or because of advice from friends or even physicians.

While a significant proportion of patients with peptic ulcer, gastro-oesophageal reflux, functional dyspepsia or irritable bowel syndrome find that chilli makes their symptoms worse, this is not the case with the majority(1). There is no evidence chilli is bad for ulcers, functional dyspepsia or irritable bowel syndrome, so avoidance of chilli is unnecessary unless the patient finds that its use makes the abdominal symptoms worse.

Is chilli good for peptic ulcer or dyspepsia?

In animal studies chilli and its active ingredient capsaicin increases gastric blood flow and protects the stomach from damage(2,3). It also encourages the healing of experimental gastric ulcer(4). In humans, while eating chilli can cause abdominal pain, there is no damage if the stomach is examined after consumption of chilli(5). Indeed, in both animals and humans, taking a dose of chilli actually protects the stomach from subsequent damage by aspirin or alcohol (3,6).

In Singapore, Malays and Indians, who eat a lot of chilli, get peptic ulcer less frequently than Chinese, who eat less chilli.(7) In another study, patients with ulcers were found to have eaten less chilli than control subjects without ulcer, even after adjusting for patients avoiding chilli because of their symptoms(8). Chilli has also been reported to help in the treatment of functional dyspepsia (9).

Should we eat more chilli, or less chilli?

Although available data are interesting, the evidence is insufficient to recommend the use of chilli to prevent or treat ulcers. It would be sensible for those patients who find that chilli exacerbates their symptoms to avoid eating chilli. However, there is no necessity to avoid chilli if it does not cause symptoms. Apart from helping you enjoy your food, it is possible that chilli may do some good to your stomach!

References

  1. Kang J Y, Tay H H, Guan R. Chronic upper abdominal pain: site and radiation in various structural and functional disorders, and the effect of various foods. Gut 1992; 33: 743-8
  2. Holzer P. Capsaicin: cellular targets, mechanisms of action and selectivity for thin sensory neurons. Pharmacological Reviews 1991; 43: 144-201.
  3. Kang J Y, Teng C H, Wee A, Chen F C. The effect of capsiacin and chilli on ethanol-induced gastric mucosal injury in the rat. Gut 1995; 36: 664-9.
  4. Kang J Y, Teng CH, Chen F C. Effect of capsaicin and cimetidine on the healing of acetic acid induced gastric ulceration in the rat. Gut 1996; 38: 832-6.
  5. Kang J Y, Yap I, Guan R, Lim T C. Chilli ingestion does not lead to macroscopic gastroduodenal mucosal damage in healthy subjects. Journal of Gastroenterology and Hepatology 1988; 3: 573-6
  6. Yeoh K G, Kang J Y, Yap I, Guan R, Tan C C, Wee A, Teng C H. Chili protective against aspirin-induced gastroduodenal mucosal injury in humans. Digestive Disease and Sciences 1995; 40: 580-3.
  7. Kang J Y, Labrooy S J, Yap I, Guan R, Lim K P, Math M V, Tay H H. Racial differences in peptic ulcer frequency in Singapore. Journal of Gastroenterology and Hepatology 1987; 2: 239-44
  8. Kang J Y, Yeoh K G, Chia H P, Lee H P, Chia Y W, Guan R, Yap I. Chili - protective factor against peptic ulcer? Digestive Diseases and Sciences 1995; 40: 576-9.
  9. Bortolotti M. Coccia G. Grossi G. Miglioli M. The treatment of functional dyspepsia with red pepper. Alimentary Pharmacology & Therapeutics 2002;16:1075-82.

Helicobacter pylori and dyspepsia

Helicobacter pylori (H pylori) is a germ found in the stomach of half of the world’s population. In about 15% of these patients, H pylori causes peptic ulcer, and in these patients successful treatment of the infection cures the ulcer disease totally. The risk of gastric cancer is also increased in people infected with H pylori although the absolute risk of this condition remains low. Many patients with functional dyspepsia (gastric pain without peptic ulcer) do have H pylori infection but in less than 10% of cases is the germ the cause of the gastric pain. For the majority of patients with functional dyspepsia or gastro-oesophageal reflux, treatment of H pylori infection will not affect the symptoms.

H pylori infection can be diagnosed by one of several methods. The blood can be tested for antibodies (serology), the stool can be tested for antigens, a breath test can be performed or biopsies taken at gastroscopy for culture, examination under the microscope or a biopsy urease test. After a course of treatment for H pylori, it is standard practice, in the majority of patients, not to check if the germ has been eradicated. However, should it be necessary to do so, serology is not helpful since antibodies may persist even when the germ has been fully treated. A breath test, a stool antigen test or an endoscopy-based test is required in this situation.

H pylori infection increases the risk of stomach cancer, but this is an uncommon disease in western countries, with or without H pylori infection, and it is not known if treating the infection in adult life reduces the cancer risk.

In western countries H pylori infection is acquired during infancy or childhood. After successful eradication in an adult, the risk of re-infection is low, around 1% per year.

Reviews on Helicobacter pylori

  1. Suerbaum S, Michetti P. Helicobacter pylori infection. New England Journal of Medicine 2002;347:1175-86.
  1. Harris A, Misiewicz JJ. Management of Helicobacter pylori infection. British Medical Journal 2001; 323:1047-50.

Diverticular disease of the colon

Colonic diverticula are pouches arising from the wall of the large intestine. They become increasingly common with age, and are found in 50% of individuals aged eighty and above, in western countries(1,2). This condition increased in frequency over the course of the 20th century in the western world(1), but is less common among African and Asian populations(2,3). These observations are consistent with the view that colonic diverticula are caused by a diet deficient in fibre, which predisposes to constipation and increased pressures in the left colon(1). Hospital admissions for diverticular disease are becoming increasingly common in England(4).

Most individuals with colonic diverticula do not have any symptoms: the diagnosis is often discovered by chance when an investigation such as colonoscopy or barium enema is performed for unrelated symptoms. The term diverticulosis is used in such cases(1,2). Other individuals report abdominal pain, bloating and irregular bowel habit, symptoms which are similar to those of irritable bowel syndrome. It may be difficult to tell if the problem is that of irritable bowel syndrome in a person who happens to have colonic diverticula, or whether that individual is suffering from painful diverticular disease(5).

In a minority of patients, the colonic diverticula become inflamed, a condition called diverticulitis(2). There may be fever, lower abdominal pain and abnormal blood tests e.g. a high white cell count. This condition usually settles with antibiotics but sometimes requires hospital admission. In severe cases abscesses or perforation can develop. These are serious conditions which require surgical treatment and can even be life-threatening. Rectal bleeding is another complication.

In western countries, the left side of the colon is involved in most individuals with colonic diverticular disease, unlike in oriental countries, where right-sided disease predominates. The reason for this difference is still unclear(2).

There is no specific treatment for people with asymptomatic diverticulosis, although on theoretical grounds a high fibre diet may be beneficial. Patients with symptoms compatible with irritable bowel syndrome should receive the same treatment as for irritable bowel.

Prompt medical attention should be sought if the pain becomes more severe, and particularly if there is fever and abdominal tenderness, in case diverticulitis has developed.

References:

  1. Painter NS, Burkitt DP. Diverticular disease of the colon: a deficiency disease of western civilization. British Medical Journal 1971: 2: 450-4.
  2. Kang J Y, Maxwell J D, Melville D. Epidemiology and Management of Diverticular Disease of the Colon. Drugs & Aging 2004:21: 211-228.
  3. Kang JY, Dhar A, R Pollok, Leicester RJ, Benson MJ, Kumar D, Melville D, Neild P J, Tibbs CJ, Maxwell JD. Diverticular disease of the colon: ethnic differences in frequency. Alimentary Pharmacology and Therapeutics 2004: 19: 765-9.
  4. Kang, JY, Hoare J, Tinto A, Subramanian, S, Ellis C, Majeed A, Melville D, Maxwell JD. Diverticular disease of the colon – on the rise: a study of hospital admissions in England 1989/90-1999/2000. Alimentary Pharmacology and Therapeutics 2003: 17:1189-95
  5. Poullis A, Barnabus A, Matthews H, Tan LT, Lim G, Kang JY. Does uncomplicated colonic diverticular disease cause symptoms ? Gut 2006;55 (suppl II):A83. (Abstract)

Constipation, diarrhoea and change in bowel habit

A survey of a British population showed that 99% of individuals move their bowels between 3 times per week to three times a day.

Diarrhoea may be defined as more frequent stools, looser stools, urgency, difficulty in control, or any combination of the above. Constipation can be taken to mean hard stools, infrequent stools, the need to strain, difficulty to fully empty the bowels, or any combination of the above.

It is often a change in bowel habit, rather than the actual frequency of defecation which is clinically important. In most individuals, a change in bowel habit is due to a functional problem i.e. the way the intestines contract, secrete and function, rather than structural disease e.g. obstruction or inflammation, problems which can be visualised. The commonest functional problem causing a change in bowel habit is irritable bowel syndrome. Other causes of a change in bowel habit include colonic cancer, inflammatory bowel disease (ulcerative colitis or Crohn’s disease), microscopic colitis, diverticular disease of the colon, malabsorption and infection.

Rectal bleeding

Rectal bleeding most commonly arises from the anus i.e. peri-anal type rectal bleeding, most commonly due to haemorrhoids or piles, or an anal fissure (or tear). Such bleeding is typically bright red, more on the toilet paper than mixed with the stools, occasionally dripping out directly into the toilet bowl. Often there is associated anal discomfort or pain.

Rectal bleeding may also arise from the colon. The blood may be dark rather than bright red, may contain clots, may be mixed with the stools and associated with mucus or slime.

Important causes of colonic bleeding include polyps, cancer, inflammatory bowel disease (ulcerative colitis or Crohn’s disease). Sigmoidoscopy or colonoscopy may be required to confirm the diagnosis.

Positive faecal occult blood tests

Sometimes bleeding occurs from the gastrointestinal tract in such small amounts that it is not visible to the naked eye, but is identifiable only by chemical testing of the stools. Patients with positive faecal occult blood test generally need to have a colonoscopy and gastroscopy to exclude disease such as colonic polyps, colonic cancer, inflammatory bowel disease, peptic ulcer or gastric cancer.

Faecal occult blood tests are used by the national bowel cancer screening program to identify individuals with an increased risk of colonic polyps or cancer.

Iron deficiency anaemia

Anaemia means a low level of haemoglobin, the red pigment contained in red blood cells. While there are multiple causes of anaemia, in many cases the underlying problem is a shortage of iron i.e. iron deficiency anaemia. In young women this is often due to heavy menstrual periods and increased demands during pregnancy, but in men and older women the problem is usually one of blood loss from the stomach or intestines. Hence patients with iron deficiency anaemia are usually referred for gastroenterological evaluation.

Important gastrointestinal causes of iron deficiency anaemia include colonic cancer and polyps, inflammatory bowel disease (ulcerative colitis or Crohn’s disease), peptic ulcer, gastric cancer and malabsorption. Uncommonly, iron deficiency can be due to a diet low in iron.

Anaemia is sometimes caused by a shortage of vitamin B12 or folic acid, as a result of reduced absorption due to disease of the small intestines e.g. celiac disease or Crohn’s disease, which can be picked up by a gastroenterological evaluation.