Stool Reducing Substances Test in Kathmandu

About this test

This simple chemical test checks whether unabsorbed sugars are spilling into the faeces, which is the tell-tale sign of carbohydrate malabsorption in the gut. When the small intestine cannot break down or absorb sugars such as lactose, glucose or fructose, those sugars travel onward to the colon where bacteria ferment them, drawing water into the bowel and producing the frothy, explosive, sour-smelling, acidic diarrhoea that worried parents so often describe. The laboratory adds a copper-based reagent (the classic Clinitest tablet) to a measured portion of liquid stool; reducing sugars turn the mixture from blue through green to orange-red, and the colour is graded to show how much sugar is present. It is most commonly requested in infants and young children with persistent or recurrent watery diarrhoea, poor weight gain, nappy rash from acidic stools, or loose motions that flare after milk feeds — picture that of secondary lactase deficiency following a bout of acute gastroenteritis, which is extremely common after the rotavirus and other diarrhoeal illnesses seen across Kathmandu, especially in the monsoon months. A positive result points the doctor towards lactose intolerance, post-infective enteropathy, or other sugar-handling problems, and is read alongside stool pH (a low, acidic pH supports the diagnosis), the clinical picture, and sometimes a trial of a lactose-free feed. Note that sucrose does not react unless the sample is first treated, so always tell us about the child's recent feeds. A negative result helps reassure that malabsorbed sugar is not driving the diarrhoea.

Sample type

Stool (fresh)

Preparation

No fasting. Bring a fresh stool sample collected within the last 1–2 hours in a clean, dry container, and keep the child feeding normally on their usual milk or diet so the result reflects what they are actually eating. Avoid mixing the sample with urine or toilet water. If you cannot reach the lab quickly, refrigerate the sample and tell us how long ago it was passed.

Turnaround time

Reports for Stool Reducing Substances are typically ready within: Same Day. Reports can be collected at the clinic during opening hours or shared via WhatsApp once they are ready.

Also known as

Other microbiology tests we run

These are routinely ordered alongside Stool Reducing Substances or as part of the same diagnostic workup.

How to book

WhatsApp is the fastest way — message us with the test name and your preferred time, and we'll confirm a slot the same day. You can also walk into the clinic at Rumba Chowk, Sanobharang any day between 7AM and 8PM, or fill in our online booking form.