Hello,
As your mother is having the symptoms of constipation and hard stools,so these anal bumps can be anal fissures or haemorrhoids/piles.The third possibility is of anal warts and herpes blisters.
Haemoorhoids is due to swelling and inflammation of veins in the rectum and anus. Increased straining during bowel movements, by constipation or diarrhea, may lead to hemorrhoids.
Symptoms of external hemorrhoids may include painful swelling or a hard lump around the anus which may itch.Treatment includes sclerotherapy,rubber band ligation,cryosurgery or Stapled Hemorrhoidectomy.Pls consult a surgeon and get it evaluated.Skin creams won’t be of any help.
I hope it helps.Take care and pls do keep me posted on how your mother is doing or if you have any additional queries.Kind regards.
Possibly she has a thrombosed pile mass.Best seen and treated.A course of metronidazole might help.