Logic Firm (was Diar-Stop)

Pictures are for illustration only.

Browse other products from the product range

Logic Firm (was Diar-Stop)

Average Rating 5/5 (24 reviews)    
View Reviews | Review this item

Item Number: DIARSANP 
Phone orders quick webcode: D3545

Select Product Option

Select one of the options below, then click 'Buy Now'

10ml (for cats and dogs under 7kg) £9.69 In Stock
24ml (for dogs between 7-30kg) £10.69 In Stock
60ml (for dogs between 30-60kg) £13.09 In Stock



You are ordering items which require a prescription, Tampering with a prescription or attempting to obtain extra unauthorise supplies is a criminal offence and will have to be reported to the authorities. “Controlled Drugs” can be only be dispensed ofter receipt of an original valid prescription sent by post. Controlled Drugs are sent via tracked, signature delivery.

  1. Place your order online or by phone
  2. Obtain a Prescription from your vet
  3. Either post the original, fax it to 01833 641032, or email it to us at [email protected] .

 I have a prescription on file
 I am sending you a prescription by email
 I am sending you a prescription by fax
 I am sending you a prescription by post


Logic Firm is an intestinal protectant for dogs and cats to help manage digestive upsets by helping to improve stool consistency and reducing fluid loss.

Logic Firm contains 4 key ingredients:

Montmorillonite – A natural clay which coats and protects the lining of the gut. Binds toxins and microorganisms.

Prebiotics (FOS - fructo-oligosaccharides) - Promotes the growth of good bacteria in the gut. Provides an energy source for the cells of the large intestine.

Electrolytes – Help restore sodium, potassium and magnesium which are lost during digestive upsets.

Dextrose – Provides an energy source for cells of the small intestine.

Each syringe provides a 3-day course.

10ml syringe for cats and dogs under 7kg
24ml syringe for dogs between 7kg & 30kg  
60ml syringe for dogs between 30kg & 60kg             

Logic Firm should not be used for more than 3 days. If symptoms persist or your pets condition worsen please consult your veterinary surgeon.


Free shipping from Hyperdrug

Value Weight Delivery Charge*  
Over £49.00 Any Weight FREE*
Under £49.00 Under 250g £2.99
Under £49.00 No weight limit £4.99

Most orders are despatched the same day and standard delivery is 3 to 5 working days from despatch. FAST Expedited delivery options are available.

Estimated " Usually shipped in" information is shown against most products


Overseas orders

Postage outside of the UK is from £4.95

Finding out delivery Charges and options before checkout

  1. Simply add an item to your basket
  2. Click view basket/Cart
  3. Click estimate shipping charges
*Free delivery and selected charges on orders over £49.00 mainland UK Parcelforce Zone1 for more information check the delivery info page.


 feefoProduct Reviews

Logic Firm (was Diar-Stop) 10ml (for cats and dogs under 7kg)

good value for money.