Why are my motions loose so often?

Most people have had a bad two days after a meal out. That settles and is forgotten. What brings someone to a clinic is different: looseness that keeps coming back, mornings organised around the bathroom, and a quiet habit of checking where the toilet is before agreeing to anything.

An episode lasting a few days and a pattern lasting months are separate problems with separate explanations. If yours has been going on for more than four weeks, it belongs in the second group.

How the bowel is behaving. Functional bowel disorders are the largest single explanation for long-standing looseness in adults, and irritable bowel syndrome is the commonest of them. The bowel is structurally normal but moves contents faster and reports sensation more loudly. The typical story is cramping that eases after passing stool, urgency in the morning or before something stressful, alternating loose and hard days, and a bowel that behaves quite differently on holiday from how it behaves on a working Monday.

What is being absorbed. Lactose is the everyday example and is relevant to a large proportion of Indian adults, in whom lactase activity declines after childhood. Milky tea several times a day, a glass of milk at night or a large bowl of curd can each be enough. Fructose, sorbitol and other sweeteners in sugar-free products behave similarly. Coeliac disease is a different matter — an immune response to gluten, under-recognised in India, and worth testing for rather than guessing at.

An infection that has left its mark. Loose motions that began abruptly after a clear episode of food poisoning or a bout of travellers' diarrhoea, and then simply carried on, are common enough to have their own name: post-infectious IBS. Giardia and amoebic infection can also persist quietly, producing weeks of looseness, gas and discomfort rather than a dramatic illness.

A metabolic or hormonal driver. An overactive thyroid speeds gut transit and often arrives alongside weight loss, palpitations, heat intolerance and disturbed sleep. Diabetes of long standing can affect the nerves supplying the bowel. These are worth remembering because the bowel is rarely the only clue.

Something inflammatory or structural. A smaller group has inflammatory bowel disease, microscopic colitis, or another identifiable cause. The features that point this way are blood, weight loss, night-time diarrhoea, and symptoms that began later in adult life.

Two things get overlooked. Medicines — metformin, magnesium-containing antacids, some blood-pressure tablets and a recent course of antibiotics all loosen stool. And constipation with overflow, where liquid slips past retained firm stool and presents as the opposite of what is actually happening.

ⓘThis information is educational and not a diagnosis.

Most recurring looseness is uncomfortable and disruptive rather than dangerous. A defined set of features changes the priority.

Seek assessment promptly if there is blood in the stool or the stool has turned black and tarry, if you are losing weight without intending to, if diarrhoea wakes you from sleep, or if fever has accompanied it for more than two or three days. Night-time symptoms deserve emphasis: functional bowel problems tend to leave you alone once you are asleep, so diarrhoea that does not is a genuine flag.

Dehydration matters more than people expect, particularly in older adults, in hot weather, and in anyone on blood-pressure or diuretic medication. Passing very little urine, feeling dizzy on standing, or a dry mouth that drinking does not relieve are reasons to be seen the same day.

Loose motions beginning for the first time after 45, a family history of bowel cancer, coeliac disease or inflammatory bowel disease, and any pattern that has continued beyond four weeks all warrant a proper assessment rather than continued self-management.

Before removing anything from your diet, spend two weeks recording what is actually happening. Note timing, form, urgency, whether pain settles after passing stool, what you ate, and what you took. The Bristol stool chart is genuinely useful here — it turns a vague description into something a doctor can work with. A fortnight of notes reveals patterns that are invisible day to day.

Then make the low-risk changes. Test milk deliberately rather than abandoning it: reduce milky tea and curd for two weeks, then reintroduce, and see whether the difference is real. Look at sugar-free chewing gum, mints and diet drinks, which contain sorbitol more often than people realise. Keep fluid and salt intake up during a loose spell — nimbu pani with a pinch of salt and sugar, or oral rehydration salts, do more than any restricted diet.

Do not begin a gluten-free diet on your own. Coeliac testing requires gluten still to be in the diet, and a self-started trial can put a clear diagnosis out of reach for months.

If looseness persists beyond four weeks despite these changes, the useful next step is a structured assessment: stool testing where infection is plausible, coeliac serology, thyroid function, a full blood count and inflammatory markers, and a review of every medicine you take. That is a shorter road than another year of narrowing the diet.