Constipation is defined as having infrequent or absent defecation with hard and dry feces.  Obstipation is the state of chronic intractable constipation.  Megacolon is simply defined as colonic dilatation.

Megacolon is a frequent consequence to chronic constipation/obstipation in the cat.  This condition, if not treated, can cause severe and serious metabolic side effects.  Early in the course of the disease, when constipation is the only problem, various drugs and treatments can be tried to help control it.  These include emollients, lubricants, and laxatives such as mineral oil and castor oil; bulk forming agents such as Metamucil and bran; enemas and suppositories; and drugs such as Cisapride which help stimulate contractions of the colon.  These measures usually have to be continued for the life of the animal, and frequently do not work well with long standing disease.

For patients that become repeatedly obstipated in spite of the above measures,  the best choice for treatment may be surgery using a procedure known as subtotal colectomy.  With this surgery, a portion of the animal’s large intestine is removed, eliminating the need for enemas and laxatives.  Depending on the individual case, other medications or dietary changes may still be needed.

Cats treated with subtotal colectomy will usually maintain a soft or semi-solid consistency to their stools.  Some cats will have very soft stools or diarrhea for a period of time following the surgery.  In the absence of other diseases, most cats treated with subtotal colectomy can go on to live normal healthy lives.