[header] How to give a cat an enema at home [title] Watch for signs of constipation. [step] If your cat is constipated, you may notice her repeatedly enter the litter box, squat to defecate, but fail to pass any feces. Your cat may strain and vocalize (meow, cry, yowl) during these attempts. 
Other symptoms can include low energy, loss of appetite, throwing-up foam or undigested food, and abdominal pain. Sometimes, you can even feel a large hard lump of feces if you gently push on your cat's abdomen.