Cat Reading Topics
Treatment of An Acutely Constipated

The first thing to do if your cat is suffering an acute bout of constipation is to contact the vet.

An acute bout of constipation can occur in a previously healthy cat or a cat with chronic constipation can experience an acute bout.

In a multi-cat household, it can sometimes be difficult to figure out which cat is producing which stool or who is not pooping. One way to sort things out is to feed each cat, in turn, a small amount of baby food beets. Be forewarned that beets may also color the urine, a harmless effect, and that will probably occur more quickly than the beets coloring the stool. Wait a couple of days before giving the beets to the next cat so you are sure whose results are whose.

There are a variety of laxatives on the market. Few of them are suitable for cats. Cats are quirky and sensitive creatures and can all too easily be poisoned by some OTC human treatments. The dailiness of chronic constipation means the treatment needs not only to be effective but very safe over the long term. What might work well enough for occasional treatment may not be suitable for long-term care. The unique sensitivity of cats as a species means any treatment, whether short or long term, must be especially safe.


Stimulant Laxatives

Stimulant laxatives are not suitable for cats.

Saline Laxatives

Saline laxatives are not safe for cats. The term 'saline' includes mineral salts such as magnesium or phosphate salts.


Do Not Use

For a cat experiencing an acute bout of constipation, delivering a remedy directly to the rectum may be the best approach, depending on the particular situation. Do, please, heed the advice in the third block under Quick Review on this page.

If you and your vet have determined that a rectally-delivered remedy is suitable, remember that any object inserted into the anus should be lubricated. Some remedies provide their own lubrication or are pre-lubricated, others require us to lubricate them. Vaseline has been the traditional lubricant but a water-based personal lubricant such as plain K-Y jelly may be a better choice, if on hand, since it more closely mimics the natural lubrication of mucous membranes. Note that only plain lubricants should be used, nothing scented or enhanced, no mint or chocolate flavors, no chemicals added for 'warming' or to 'tingle on contact' please!

Understanding the construction of the anus will make the job of inserting a suitable and suitably lubricated object, whether a suppository or a thermometer, into a cat's anus much easier. The anus has not one but two sphincters. You could think of this as a storm porch on the back of the house. The outer sphincter is under voluntary control, the inner sphincter is not. Normally all traffic is one-way which means the anus does not expect traffic in reverse, something coming in rather than going out, so initially it is a bit of a surprise. Gentle steady pressure causes the outer sphincter to relax, to 'answer the door'. The cat also appreciates this approach. No one wants someone to come busting through the door when a polite but insistent knocking will result in a warmer welcome.

A cold object causes involuntary muscle contraction so prewarm a thermometer, just enough to take the chill off but not enough to affect its reading.

Remember to talk with your cat. Show your cat what you plan to use and explain why and what you plan to do. Talk as from one adult to another, which this relationship is after all. Your cat is an intelligent being and while not every word will be understood, cats pick up on our intent and our intent informs our action. If we think, for instance, that taking a temperature or using a micro-enema requires us to 'shove something up a cat's ass,' that is exactly what we will do with predictably negative results. If, instead, we imagine using gentle steady pressure and visualize gliding in smoothly, that is more likely to happen because our movements will follow. It is far easier to work with a cooperative cat; take the time to elicit cooperation. Cooperation is the kinder and safer approach.Kitten



  • Warm water Body temperature water is quite safe when delivered as a little enema, depending on the amount delivered! A cat is a small creature, much smaller than a human. If a cat is constipated, we can assume the rectum is probably occupied by poop and adding too much water stresses the situation further. The point of a warm water enema is not to flush the colon, like preparation for a colonoscopy or bowel surgery, but to increase rectal volume just enough to provide a sufficient signal to the enteric nervous system that something needs to be done. It does not take much water volume to give that signal. Plain warm water will not penetrate or soften the stool well. If the accumulated stool in the rectum is too large to pass comfortably through the anus in response to the signal, and is rock hard, even a small enema can be very uncomfortable for the cat unless the stool is first softened. A plain water-based personal lubricant product can be added to the water in a 50-50 mix but the total amount of liquid used should be kept small, under 10 ml. A level measuring teaspoon contains 5 ml so less than two level teaspoonsful should be used, a little at a time, not the full amount if the situation is unclear. Remember those stretch receptors in the bowel wall which communicate with the brain's vomiting center? Too much liquid injected into the bowel may result in your cat vomiting rather than pooping. Start low and go slow!
  • Feline Pet-ema – Sized for cats and available without prescription, Feline Pet-ema contains Dioctyl Sodium Sulfosuccinate (DSS) 125 mg., a stool softener, in glycerine, with Sorbic Acid as a preservative. Each Feline Pet-ema holds 6 ml of fluid, to be deliverePet-Emad rectally via a prefilled disposable syringe. The act of inserting anything into the rectum provides stimulus, both in volume increase and nerve stimulation, and the enema volume itself may provoke action. The glyercine in the solution helps draw water while the stool softener facilitates in rehydrating the stool to help soften. See Glycerine and Stool Softeners below to understand their action.
  • DocuSol® Kids - A more recent offering in the mini-enemaDocuSolKids1 department, this product contains a stool softener, Docusate Sodium 100 mg., in a base of polyethylene glycol (an osmotic laxative, see below) and glycerine. The volume is 5 ml. and comes five mini-enemas to a box.
  • FLEET® Liquid Glycerin Laxative SuppositoriesFLEET's term for a disposable pre-lubricated micro-enema for human use which contains only glycerine. READ THE LABEL! FLEET also offers saline enemas which should NOT be used for cats! Glycerine EnemaAs we learned in Gut 101, the digestive tract is self lubricating but the combination of insertion, irritant action of glycerine as well as its hydroscopic properties, and the additional volume and lubrication, may help relieve the acute situation. See however the warning about impacted stool. The adult version is 7.5 ml; deliver only part of that volume initially. Some liquid will remain in the applicator. The pediatric version, Pedia-Lax Liquid Glycerin Laxative Suppositories, contains 4 ml each. You can administer less initially, reserving the remainder to use if necessary after you are aware of your cat's individual response to this treatment.
  • MICROLAX® – Another micro-enema, made by Pharmacia & UpjohnMicrolax, MICROLAX® contains sodium citrate dihydrate, sodium lauryl sulfoacetate, glycerin, sorbitol, sorbic acid, and distilled water. Each little enema provides 5 ml of liquid. While not a veterinary product, the ingredients are used in veterinary medicine.

Please note! When using these little enemas, maintain steady pressure on the plunger or especially the bulb when withdrawing the device so that no suction is created. You do not want to exert suction against those tender rectal tissues.



  • Glycerin/Glycerine - Glycerine acts as an irritant to the gut mucosa and therefore to the ENS, to the nerves in the gut wall, which kicks them into higher gear. Glycerine is also hygroscopic which means it attracts water to itself making the glycerine even slipperier than normal, providing additional lubrication and helping to soften stool with additional water. As we learned in Gut 101, Glycerine Suppositoriesthe digestive tract is self lubricating but the combination of the insertion of the suppository, which delivers a signal to the ENS, plus the irritant action of glycerine acting on the gut wall, plus the additional lubrication may help relieve the situation. Only the single ingredient glycerine should be used as a suppository, in a pediatric size. Glycerine suppositories can be pared down easily to a smaller size if necessary. You can use a vegetable peeler. Be sure to smooth any rough edges created.
  • Instead of a glycerine suppository, you can first try dipping the end of a Q-tip in liquid glycerine, thoroughly saturating it. Then gently and carefully insert the saturated Q-tip into the rectum and remove it, repeating three or four times. This will not only lubricate the passage but stimulate the voiding reflex and draw some water..Kitten


'Lubricant' Laxatives

  • Olive oil – Technically a cholagogue (see Glossary), not a lubricant laxative, olive oil has mild laxative properties when a larger dose is given. A larger dose for a cat is a small amount! For a mild bout of constipation, a quarter teaspoonful of olive oil can be given for acute treatment but cats require animal fat sources, not plant oils, so olive oil is not suitable for ongoing care. Olive oil contains terpenic acids and phenolic compounds which a cat's liver is not able to properly detoxify. Some pharmacies carry small bottles of pharmaceutical-grade olive oil. Do not force any oil into the mouth of a cat.
  • Laxatone and other 'hairball remedies' – Hairball remedies are petrolatum based. Petrolatum, essentially Vaseline, is a more solid cousin of liquid mineral oil. Because oral petrolatum products can deplete fat-soluble vitamins as they pass through the digestive tract, hairball remedies have some vitamins added. Because cats are Hairball Remediescats, the remedies are flavored to tempt the cats. On hair, hairball remedies act like creme rinses to keep hair from tangling into a ball although they will not untangle a ball which has already formed. When given as a laxative, the idea is to lubricate the stool. As we know, the gut is self lubricating but additional lubrication may help during an acute bout of constipation. Petrolatum coats the stool with what we could call a reverse raincoat, a waterproof coating which prevents more water from being resorbed away from the stool into the body, keeping the stool from getting drier and harder and thus making it easier to pass. Several doses of hairball remedy spaced a few hours apart may be enough to get a cat over an acute bout of constipation but these remedies are not a long-term solution and they must travel through the digestive tract to reach their goal. Hairball remedies should never be forced into a struggling cat's mouth. If they are aspirated, they can cause lipoid pneumonia which is difficult to impossible to treat.
  • Mineral OilMineral oil – Plain liquid mineral oil should never be delivered orally to a cat. Mineral oil is tasteless and odorless and too easily aspirated into the lungs. This can result in lipoid pneumonia which can be deadly. Do not give a cat liquid mineral oil by mouth.

Lubricant laxatives based on petrolatum are used because, since they are indigestible, they remain in the gut rather than being absorbed into the body as dietary fats/oils. They can be helpful during an acute bout of constipation but are not the most healthful choice for ongoing care for a cat with chronic constipation, they are recommended for short-term use.

As discussed under Suppositories, a glycerine suppository or a Q-tip saturated with liquid glycerine also qualifies as a lubricant laxative. Form does not necessarily define function.


Stool SoftenersKitten

  • Colace contains docusate sodium, a surfactant or wetting agent which makes water 'wetter'. We use the same principle when washing greaCapsulessy pots and pans with dish detergent. Once stool has lost water, it resists rehydration by plain water alone as fatty residues in the stool can render it waterproof – oil and water do not mix. Docusate acts in two ways to relieve constipation. It lowers the surface tension of water which allows water to penetrate hard dry stools, thus increasing volume. This also makes the stools softer and easier to pass, thus reducing straining. Docusate also has a mild stimulant effect on the gut. It triggers nerve endings in the large intestine and rectum, causing the muscles to contract more often and with greater force which moves the contents of the colon into the rectum and out into the litter box. If the reluctant stool is large, clearly it is better to have the stool softened before it is forced out.
  • Docusate sodium tastes bitter! If a cat senses a bitter taste, the cat will produce extra saliva and foam at the mouth in an involuntary attempt to dilute and wash out what is perceived as a toxin. Severe foaming could cause breathing and swallowing difficulties for your cat. Therefore, if a vet approves use of Colace/docusate sodium, avoid the taste and the risk entirely by pilling a Colace capsule, 50 mg. size, and chase the capsule with food or water as discussed in Gut 101 under Esophagus.
  • Consult your vet!
  • An oral medication needs to make the trip from mouth to bowel. Oral stool softeners are not a quick fix, it takes time to rehydrate the stool.


Osmotic Laxatives

  • Lactulose – Lactulose is a sweet thick liquid offering an indigestible sugar which acts as an osmotic laxative. In humans it apparently is a fermentable fiber for the gut bacteria. I have read that it is for cats, I have read that it is not. The byproducts of the gut bacteria help Osmotic Laxativesregulate pH in the colon, and it is the pH that influences how much water will be retained in the stool. Lactulose alone influences the pH of the bowel, has the necessary slightly acidifying effect to cause water retention thus increasing volume and signaling the ENS. Lactulose requires a prescription from the vet in the U.S.
  • MiralaxMiralax , now an OTC drug, is polyethylene glycol, PEG 3350. The number 3350 describes its average molecular weight and distinguishes Miralax from polyethylene 300 or polyethylene 400, for instance. Polyethylene glycol is not ethylene glycol, more familiarly known as antifreeze. Miralax retains water in the stool or the bowel depending on when it is administered in relationship to meals. See Prevention for more information about Miralax.Kitten

Both Lactulose and Miralax are dose-to-effect drugs with a normal stool as the goal. The intent is not to flush out the cat. If the cat has impacted stool, osmotic laxatives are not suitable until that situation is relieved. We do not want to create pressure behind a dam! In any event, osmotic laxatives do not 'catch up with' the stool already formed to act as stool softeners. They are better used to prevent trouble than to deal with a serious bout of constipation and are not suitable for impacted stool.

See below for learning to do a simple colon examination at home to better evaluate the situation or consult your vet to determine current status.

Paw Print Two

By now, we can see common patterns among these seemingly different approaches. First, they involve water one way or the other, even if that is not apparent on the surface:

  • stimulating action by the insertion of a suitable object causes the stool to move sooner rather than later, before it stays put longer and loses even more water
  • simply increasing volume in the rectum stimulates action so adding a small amount of a suitably safe liquid may be sufficient, but again observe the caution
  • triggering action through stimulation or irritation causes the stool to move sooner rather than later, before it stays put longer and loses even more water
  • lubricant laxatives and suppositories irritate and cause stool to move sooner rather than later
  • stool softeners allow water to penetrate the stool which increases stool volume which triggers action by signaling to the bowel
  • osmotic laxatives draw water in or ensure water retention which increases volume

Laxatives work through common actionsphysical and/or chemical stimulation, and/or volume increase.


We see different brand names, different chemical names, different appliances, but how does the bowel 'see' it?

That question has been answered, in part, in the preceding information. The bowel receives signals through its nervous system, from the pressure of the stool, in the dance we call pooping. In time of need, laxatives can mimic those signals and our goal is to use laxatives that most closely mimic the natural process without going overboard. If a little stimulation will do the job, we do not want to overstimulate.

However, there remains a further problem for us – we have no idea of the situation in the bowel. Is the stool too large to pass easily? A large hard lump that needs softening first? Small shriveled bits unable to initiate bowel action? Is the stool sitting this dance out or has it taken over the lead completely with the bowel trying to keep up?

Remember these illustrations?

Cat Digestion InvertedCat Large Intestines 








There is that descending colon, running underneath the cat's spine, behind the ribs and out between the hind legs. That is, in part, what a vet is feeling when he performs an abdominal exam on a cat.Kitten

You can learn to feel the contents of the colon, to learn what might be waiting in that chute. Done properly, this will not hurt your cat but you do not want to learn during a time of crisis. If you have another cat in the house, you can practice on the unconstipated cat first. In any event, make this a pleasurable process for both you and your cat or cats. There is no deadline, you can take a week or a month to learn, indulge in a little practice when you and your cat are having a cuddle.

Cat Abdominal Exam

Depending on the girth of the cat, you may be able to reach over the spine with one hand as I could with our slender cat, Jenny Anydots, fingers on one side and thumb on the other, to feel the bowel. With a more generous cat or if your hands are small, you can use one hand on either side of that space behind the ribs and in front of the hind legs. Take your time, your fingers will learn to see, to first find the colon and then to distinguish the muscle of that tube from its contents. We can identify by feel the contents of our pockets or handbag so our hands and brains are well equipped to learn this new application.

The bladder is located toward the ribs and below the colon and does not feel like a tube but like a little balloon with more or less inflation depending on how full of urine it is at the time. Of course you do not want to be putting pressure on the bladder.

You can also feel from the belly side to examine that last section of bowel between the hind legs that exits at the anus. You may even be able to help work out anything waiting right at that door by gently massaging toward the anus.

A manual exploration must be gentle and slow and relaxed. The learning process cannot be rushed and if you are stressed, your cat will only become more stressed. Be sure to explain to your cat what you are doing and why, and report what you learn.

If you feel nothing and yet your cat has not been pooping and you are concerned your cat is constipated, a quick x-ray at the vet's may be necessary to determine whether there is impacted stool higher up in the large bowel. Sometimes absence of evidence is not evidence of absence.

Learning to physically monitor the status of the constipated cat's situation helps us select the best approach and when it is time to head immediately to the vet for assistance.

Once any crisis has passed, it is time to focus on prevention. In fact it is always time to focus on . . .






Search Query


“Cats require purity and simplicity.” – SEM

Copyright © FelineConstipation.Org 2010. All

MacHighway - Mac Powered Web Hosting For Mac Users, by Mac Users since 1997

Feline Constipation  Org
Cat on Small Rug Looking at Reader
The First Lesson
Gut 101 – Full Version
Gut 101 – Condensed
Gut 102 - Full Version
Small Intestine
Large Intestine
Gut 102 – Condensed
Gut Bacteria and Fiber
What Goes Wrong?
Acute Treatment
Saline Laxatives
Stimulant Laxatives
Lubricant Laxatives
Stool Softeners
Osmotic Laxatives
Fiber or Prebiotics
Vitamins and Minerals
Osmotic Laxatives
Contact and More