Gastrointestinal system
Digestive system: medicines & conditions
The digestive system breaks down food and absorbs nutrients, from the stomach through to the bowel. Gut medicines tackle a wide range of problems — reducing stomach acid, settling nausea, easing constipation or diarrhoea, and calming inflammation in the bowel.
Education and reference only. This hub explains which medicines relate to the digestive system and why — it deliberately contains no doses and is not a substitute for advice from your doctor or pharmacist. Always check the BNF and the product labelling for prescribing detail.
About the digestive system
Because the gut handles everything we swallow, its medicines span many roles: acid-suppressing drugs (such as proton-pump inhibitors and H2 blockers) for reflux and ulcers, laxatives and anti-diarrhoeal drugs to regulate bowel habit, anti-sickness medicines, and powerful anti-inflammatory and immune-modifying treatments for inflammatory bowel disease. Some are taken short-term for symptom relief; others are long-term. The themes that matter are taking certain drugs at the right time relative to food, not ignoring "alarm" symptoms that need investigation, and reviewing long-term acid suppression to keep it appropriate.
What this covers
- Acid reflux (GORD) and stomach ulcers
- Irritable bowel syndrome and bowel habit
- Nausea, vomiting and constipation
- Inflammatory bowel disease
Conditions in this area
Digestive system conditions (82)
Each links to a dose-free guide showing which medicine classes are used and how treatment is approached.
Digestive Abnormal liver blood tests Abnormal results on liver blood tests, often found by chance, which have many causes — frequently minor and reversible —… Digestive Achalasia A rare condition where the muscle at the bottom of the food pipe fails to relax and the food pipe loses its normal movem… Digestive Acid reflux & GORD Stomach acid rising into the gullet, causing heartburn and an acid taste — managed with lifestyle change and, where need… Digestive Acute cholecystitis Sudden inflammation of the gallbladder, usually from a gallstone blocking it, causing severe upper right tummy pain — ne… Digestive Acute diarrhoea A sudden bout of loose or watery stools — usually caused by a passing viral infection and getting better on its own, whe… Digestive Acute pancreatitis Sudden inflammation of the pancreas causing severe upper tummy pain, most often from gallstones or alcohol — needing urg… Digestive Alcohol-related liver disease Liver damage caused by drinking too much alcohol over time, often silent until advanced — where stopping or reducing alc… Digestive Alcoholic hepatitis Inflammation of the liver caused by drinking alcohol, ranging from mild to a severe, life-threatening illness — where st… Digestive Anal abscess A painful collection of pus near the anus from an infection, causing a swollen, red, tender lump — needing prompt draina… Digestive Anal cancer A relatively uncommon cancer of the anus, often linked to HPV, causing symptoms such as bleeding, pain or a lump — where… Digestive Anal fissure A small tear in the lining of the anus that causes sharp pain when passing stools and bright-red bleeding — usually heal… Digestive Anal fistula A small tunnel that develops between the inside of the anus and the skin nearby, usually after an abscess — causing disc… Digestive Appendicitis A painful swelling of the appendix that is a common surgical emergency — where tummy pain that starts near the navel and… Digestive Autoimmune hepatitis A condition where the immune system attacks the liver, causing inflammation that can lead to scarring — usually well con… Digestive Barrett's oesophagus A change in the cells lining the lower gullet (oesophagus) caused by long-term acid reflux — usually it causes no sympto… Digestive Bile acid diarrhoea A common but under-recognised cause of chronic watery diarrhoea, where bile acids irritate the bowel — often effectively… Digestive Bloating A common feeling of a swollen, full or tight tummy, usually harmless and related to digestion — but persistent bloating … Digestive Bowel incontinence Difficulty controlling bowel movements, leading to leakage of stool — common, often treatable, and important to seek hel… Digestive Bowel obstruction A blockage that stops food and fluid passing through the bowel, causing tummy pain, vomiting, bloating and constipation … Digestive Bowel polyps Small growths on the lining of the bowel, usually harmless but sometimes able to turn into cancer over time — which is w… Digestive Cholangitis A serious infection of the bile ducts, usually behind a blockage such as a gallstone, causing fever, jaundice and tummy … Digestive Chronic pancreatitis Long-term inflammation that permanently damages the pancreas, causing recurring pain and, over time, problems digesting … Digestive Coeliac disease An autoimmune condition where eating gluten damages the lining of the small intestine, causing digestive symptoms and po… Digestive Constipation Passing stools less often than usual or finding them hard, dry or difficult to pass — usually improved by changes to die… Digestive Constipation in children A very common problem in children of hard, infrequent or difficult stools — usually not serious and treatable, though it… Digestive Cyclical vomiting syndrome A condition causing recurrent episodes of severe vomiting with well periods in between, more common in children — where … Digestive Cyclospora A parasite that causes watery diarrhoea and tummy upset, usually caught abroad from contaminated food or water — treatab… Digestive Diverticular disease A very common condition in which small pouches form in the wall of the large bowel — often causing no problems at all, b… Digestive Dumping syndrome A condition, usually after stomach surgery, where food moves too quickly into the small intestine, causing symptoms afte… Digestive Dysentery An intestinal infection causing diarrhoea with blood or mucus, tummy cramps and fever — usually from contaminated food o… Digestive Eosinophilic oesophagitis An allergic-type inflammation of the food pipe that causes difficulty swallowing and food getting stuck — managed with d… Digestive Fatty liver disease A build-up of fat in the liver, usually linked to weight, diabetes and metabolic health — very common, often silent, and… Digestive Food intolerance Difficulty digesting or reacting to certain foods, causing symptoms like bloating and tummy upset — unpleasant but, unli… Digestive Food poisoning Illness from eating contaminated food, causing sickness, diarrhoea and tummy cramps — usually mild and settling within d… Digestive Functional dyspepsia Persistent indigestion-type symptoms — such as upper tummy discomfort and fullness — where no ulcer or other structural … Digestive Gallbladder cancer A rare cancer of the gallbladder that often causes few early symptoms, so signs such as jaundice, tummy pain and weight … Digestive Gallbladder polyps Small growths on the lining of the gallbladder, usually found by chance on a scan — most are harmless and just monitored… Digestive Gallstones Hard stones that form in the gallbladder, often causing no symptoms but sometimes triggering severe pain or complication… Digestive Gastritis Inflammation of the lining of the stomach — causing indigestion-type pain, nausea and feeling full — usually managed by … Digestive Gastroparesis A condition where the stomach empties too slowly without a blockage, causing nausea, fullness and bloating — managed wit… Digestive Gilbert's syndrome A very common, harmless inherited condition causing mild, fluctuating jaundice at times of stress or illness — needing n… Digestive Haemochromatosis An inherited condition in which the body absorbs too much iron, which builds up and can damage organs — effectively trea… Digestive Haemorrhoids Swollen blood vessels in or around the anus that can cause bright-red bleeding, itching, discomfort and lumps — usually … Digestive Hepatitis B A viral infection of the liver spread through blood and body fluids — often clearing in adults but sometimes long-term, … Digestive Hepatitis C A viral liver infection spread mainly through blood, often with no symptoms for years — now curable in most people with … Digestive Hiatus hernia A condition in which part of the stomach slides up through the diaphragm into the chest — often causing no symptoms, but… Digestive Hiccups Sudden, involuntary contractions of the breathing muscle causing the familiar "hic" sound — almost always harmless and b… Digestive Hirschsprung's disease A condition present from birth where nerve cells are missing from part of the bowel, causing severe constipation and blo… Digestive Histamine intolerance A suggested sensitivity to histamine in foods, causing symptoms like flushing, headaches and tummy upset — managed by re… Digestive Inflammatory bowel disease (IBD) A group of long-term conditions — mainly Crohn’s disease and ulcerative colitis — in which the immune system causes infl… Digestive Irritable bowel syndrome (IBS) A common long-term gut disorder causing abdominal pain and changes in bowel habit without damage to the bowel — managed … Digestive Ischaemic colitis A temporary reduction of blood flow to part of the large bowel, causing tummy pain and bloody diarrhoea — usually mild a… Digestive Itchy bottom Persistent itching around the anus, which is common and usually not serious — often improved by good hygiene and avoidin… Digestive Lactose intolerance Difficulty digesting the sugar (lactose) in milk, causing bloating, wind and diarrhoea after dairy — managed by limiting… Digestive Meckel's diverticulum A common, usually harmless small pouch present from birth in the small bowel — occasionally causing bleeding, inflammati… Digestive Mesenteric ischaemia A reduction or blockage of the blood supply to the intestines, which can be a sudden emergency or a chronic problem — ne… Digestive Microscopic colitis A cause of chronic watery diarrhoea in which the bowel looks normal but is inflamed under the microscope — usually contr… Digestive Mucositis Painful inflammation and ulceration of the lining of the mouth or gut, a common side effect of some cancer treatments — … Digestive Nausea and vomiting Feeling sick (nausea) or being sick (vomiting) is a symptom rather than a disease in itself, so the most important step … Digestive Non-alcoholic fatty liver disease A very common condition where fat builds up in the liver, usually linked to weight and metabolism — often harmless early… Digestive Oesophageal atresia and tracheo-oesophageal fistula A rare condition present from birth where the food pipe does not form properly and may connect to the windpipe — treated… Digestive Oesophageal spasm Abnormal, sometimes painful contractions of the food pipe that can cause chest pain and difficulty swallowing — usually … Digestive Oesophageal stricture A narrowing of the food pipe that makes swallowing difficult, often from acid reflux — usually treatable by stretching t… Digestive Pancreatic cancer A serious cancer that often causes vague symptoms and is diagnosed late — so awareness of signs such as jaundice, weight… Digestive Peptic ulcer disease Open sores in the lining of the stomach or duodenum, usually caused by Helicobacter pylori infection or anti-inflammator… Digestive Peritonitis Inflammation of the lining of the tummy, usually from an infection or a burst organ such as the appendix — a medical eme… Digestive Pilonidal sinus A small tunnel or pit in the skin at the top of the buttock cleft, which can become infected and painful — treated with … Digestive Primary biliary cholangitis (PBC) A long-term autoimmune liver condition in which the small bile ducts are gradually damaged, which can lead to liver scar… Digestive Primary sclerosing cholangitis A rare, long-term condition causing inflammation and scarring of the bile ducts, often linked to inflammatory bowel dise… Digestive Problems swallowing pills Difficulty or anxiety about swallowing tablets or capsules, which is common — where simple techniques often help, and al… Digestive Proctalgia fugax Sudden, short-lived episodes of intense pain in the back passage from muscle spasm — harmless but distressing, and usual… Digestive Proctitis Inflammation of the rectum — the last part of the bowel — causing rectal bleeding, mucus, an urgent or frequent need to … Digestive Pyloric stenosis A condition in young babies where the muscle at the stomach outlet thickens, causing forceful vomiting after feeds — tre… Digestive Rectal bleeding Blood from the back passage, which usually has a minor cause such as piles but should always be checked, as it can occas… Digestive Rectal prolapse When part of the lower bowel (rectum) slips down and protrudes through the anus, causing a bulge, discomfort and sometim… Digestive Small intestinal bacterial overgrowth (SIBO) An excess of bacteria in the small intestine, causing bloating, wind and digestive symptoms — treated with antibiotics a… Digestive Thrombosed haemorrhoid A painful, firm lump at the anus caused by a blood clot in a haemorrhoid — very painful for a few days, then settling, w… Digestive Travellers' diarrhoea Diarrhoea that develops while travelling, usually from contaminated food or water — typically mild and short-lived, mana… Digestive Viral hepatitis Inflammation of the liver caused by viruses (hepatitis A, B, C and E) — some types clear on their own, while chronic hep… Digestive Volvulus A twisting of a loop of bowel that blocks it and can cut off its blood supply — a medical emergency causing severe tummy… Digestive Wilson's disease A rare inherited condition in which copper builds up in the body, damaging the liver and brain — treatable with lifelong… Digestive Wind and flatulence Passing gas (burping and flatulence) is a normal part of digestion — excessive or troublesome wind is common and usually…
Medicine classes
Medicines for the digestive system (13)
Each links to a full, dose-free guide — what it is, how it works, who can and cannot use it, side effects, interactions and FAQs.
Aminosalicylates Gastrointestinal The mainstay for mild-to-moderate ulcerative colitis — to treat flares and maintain remission.… Antacids and alginates Gastrointestinal Fast, on-demand relief for heartburn and indigestion — often the sensible first step.… Antidiarrhoeals Gastrointestinal Short-term relief for acute diarrhoea — with clear limits on when not to use them.… Antiemetics Gastrointestinal Drugs that prevent and treat nausea and vomiting — the right choice depends on the cause.… Antispasmodics Gastrointestinal Ease the cramping pain of irritable bowel syndrome and gut spasm.… Domperidone Gastrointestinal Eases nausea and helps the stomach empty — now used short-term because of heart-rhythm cautions.… H2-receptor antagonists Gastrointestinal Acid-reducing drugs for heartburn and ulcers — a gentler step than PPIs in some situations.… Laxatives Gastrointestinal Different types for different problems — chosen by cause and stool consistency.… Oral rehydration salts Gastrointestinal Replace water and salts lost in diarrhoea and vomiting — the mainstay of treating dehydration.… Orlistat Gastrointestinal Blocks fat absorption to support weight loss alongside diet and activity.… Pancreatic enzyme replacement Gastrointestinal Replaces digestive enzymes so food can be absorbed in pancreatic insufficiency.… Proton pump inhibitors Gastrointestinal Powerful acid-suppressing drugs for reflux and ulcers — names ending in "-prazole".… Ursodeoxycholic acid Gastrointestinal A natural bile acid that protects the liver in primary biliary cholangitis and treats some other bile problems…
By active ingredient
Common digestive system medicines by name
Individual, dose-free guides to specific active ingredients (and their brands) in this area:
Clinical formulas & tools
Calculators used in this area
Risk scores and formulas that inform assessment and treatment decisions for the digestive system:
Answers
Digestive system: frequently asked questions
What medicines are used for the digestive system?
This system includes 13 medicine classes — such as aminosalicylates, antacids and alginates, antidiarrhoeals, antiemetics. Each links to a full, dose-free guide covering what it is, how it works, who can and cannot use it, side effects and interactions.
Which conditions affect the digestive system?
Common conditions in this area include Abnormal liver blood tests, Achalasia, Acid reflux & GORD, Acute cholecystitis, Acute diarrhoea and more. Each condition page shows the medicine classes used to treat it and why.
Do these pages give doses?
No. Every page on this site is dose-free. We explain which medicines are used and why, but doses depend on the individual and the exact product — always confirm with your prescriber, the BNF and the product labelling.
Is this a substitute for medical advice?
No — it is education and reference only. It helps you understand this body system and its treatments, but decisions about your own care should always be made with a qualified clinician.
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